Spoiler 
SS13 Guide(NEW)
If you're too lazy to look through the wiki, this is basically a quick-guide to how the station works :
THE ENGINE
The engine is basically a mini-blackhole contained within engineering, while the Engineers, those that maintain the engine, is usually ignored, never underestimate them : They keep the station running, without the engine, it just takes 20 minutes for the entire station to fall into total power failure without a running engine(Even if the Solars are setup), and keeping the singularity is a containment field
Should you gain access to engineering, never walk into the Singularity room unequipped, you'll need Mesons(The green goggles that allow you to see through walls, but not see people/objects through walls) or you'll become sick just by looking at the singularity, and if there ain't walls, you'll get sucked in and turned into atoms(No Corpse, Thus unrevivable), and when going into the singularity room, DO, NOT, FUCK, AROUND, see those emitters shooting those blue lasers? they power the containment field generators, the blue lasers(Actually power Emittage) is one of the most lethal things on the station, if struck, you can easily obliterated, and if you're lucky enough, you might just simply be thrown into Critical(Will be explained soon), even then, don't even go near the emitters, the emitters need to be shooting the Generators to power the containment field, each generator needs one emitter shooting at it, if a single generator loses power, it's like a domino effect : The other generators fail, and the Singularity gets Unleashed
An Unleashed Singularity is a cloud of instant death, it'll move around the station, eating EVERYTHING, walls, floor, fire extinguishers, unsuspecting crew, monkeys, machines, wires, EVERYTHING, and this is actually why you run from the singularity, while you can eliminate a unleashed singularity, it requires a Bomb(Or two, or three), percision and timing, by exploding a bomb right when it encounters the singularity, you can eliminate it, however, too early, the bomb'll explode in your face/Too far, too late, the bomb will get eaten by the blackhole(No explosion), however, the singularity moves slowly, and you do not get sick looking at a unleashed singularity without mesons, unfortunately, it still sucks everything in, and leaves a wake of freezing, depressurized space in it's trail, you'll need oxygen to get past the damage that it causes
HEALTH
Health is basically, how your character is faring, it is represented by a cherry green person-symbol with a small 100 across it, it means that you are perfectly fine, should you be damaged, the 100 disappears, and your damage is represented by simply a coloured man(And the entire small unit), green = not so perfect, but still fine, yellow = moderately damaged, get some help, Red = you are badly injured, Go to medbay, now
If you are damaged beyond 0(Yes, there are negative health values), you're thrown into Critical, in this state, you are knocked uncoinscious, and your health will degrade, slowly but surely, this is when you pray that someone finds you and drags you to medbay, and that the doctors are competent enough to actually inject inaprovaline and toss you into cryo instead of injecting a mass of tricordrazine and forgetting about you, Tricord can be extremely good when you are damaged but talking and walking, but it is useless when you are in Critical
THE LAW(Aka Security)
They are the guys in Red jumpsuits and wearing armor, there isn't an excuse as "I didn't see the security officer" because they are extremely visible, They are the security guards, sometimes called "Security" or more likely "Sec", while they have only 4-5 officers, do not underestimate them, a single Security officer can subdue three everyday unequipped crewmembers, and even if facing a armored Crewmember/Badguy(If by theft, manufacturing or starting as Syndicate), a Officer with good skill(Actually, you just need to be faster) can stun and arrest the suspect, Security officers are nearly the same as Today's Policemen, They have Tasers, batons and Handcuffs, except for a technological difference : tasers are now long-range and instead use a bolt of electricity, Batons are now Stun batons, which can stun people/aliens with just a single strike, an exception? the handcuffs, there are no differences between today's police handcuff and SS13 Sec guard's handcuff, so you know how they work
Looking over the Security Guards is the Heads of Security, or, HoS, in Goonstation, the HoS are the most skilled, For it is a Application-only job, and only the best are selected, only the Captain is on-top of the HoS, but really, the HoS is (Usually) the most powerful person on the station, with skill, a unique power and distinction
The SS13 version of the prison is the Brig, here, the officers rule, they can dictate how long a law-breaker stays, where the law-breaker stays, and how(Keep them handcuffed? strip them? or let them keep their stuff?), and don't worry about being locked up a really long time/permanently for doing a minor crime(Like theft), doing so is frowned upon(Unless if they have a Good reason, like suspected revolutionary or suspected changeling)
CAPTAINS
The king of the Station, the Captain, while the Captain isn't a app-only job(Anyone can be a Captain), people tend to stay away from captainship, it is really hard, when encountering a Captain, keep to yourself, try to stay out of melee-range, and don't talk to him/her if you don't have to, as the most important guy on the station, there is a huge target on his/her back, and gets really edgy when people stand around close not doing anything
However, there is a Exception : Other heads of staff, as well as Security, they can stand right next to the captain idle and the capt won't get real suspicious, you know why, if the Captain tells you to do something, try to do it, the capt is the authority around, The captain is not as visible as Sec, but has one unique thing : The captain's Suit and armour is green, and there isn't much around the station that's green, so you'll know when you see the captain
HEADS OF PERSONNEL
third most important guy on the station, the Heads of personnel(Usually called HoP) is fancy-talk for human resources director, they basically keep the station in order and occupied by assigning new crew to different tasks/Change Jobs, they can replace dead crewmembers in different jobs like doctoring, engineering, research and security, but otherwise, they ain't that notable
Heads of Personnel are Unique in the players, the HoP will Either die a coward's death or be a complete badass that will root out the traitor and be the best guy in town, there is no grey area dealing with them, oh, and a Drunk HoP is a Legendary Fighter that will shrug off a huge volley of Lethal Lasers and stunning tasers and be capable of killing a Syndicate in a single punch to the head, watch out for them(Or, rather, don't let them even get close to the booze)
CE/RD/HS
Shorts for Chief Engineer, Research Director and Head Surgeon, they are basically Heads of the department they are assigned to, obviously, the Chief engineer is basically the boss of the engineers(And usually the one that get the blame when the power goes out), the Research director is the boss of research(And fingers are pointed at him when a Research disaster happens), the Head Surgeon is the boss of the Doctors(Actually, most people forget that the Head Surgeon is even the boss, hell, people even forget that the HS is a Head of staff)
A CONVERTING FORCE
One enemy that i forgot to mention, are Revolutionaries, they are the enemies of the station, and they're here to kill ALL heads, there are Three Revolutionary heads at the beginning, but they have a special ability : they can turn a Flash(Basically a Blinding self-defense weapon) into a brain-washing item, by blinding a Crewmember(NOTE, doesn't work on Heads or Security), they can convert the crewmember from a Loyal Nanotrasen employee, into a Revolutionary, they can't turn flashes into brain-washers, but atleast they are pawns of the Rev heads, and they have the same objective : murder all heads of staff
DOCTORING
Doctoring in SS13 is as complex as Doctoring in Real-life, there are several basic field-medicine, The Bruise pack, made for healing physical wounds(Security is well-stocked with them, for obvious reasons), Ointment, Made for healing burns(Plentiful in Research, those guys get alot of fires)
However, if the damage/burns are too severe, field medicine can be disastrous, applying bruise packs to heavily wounded people can actually BURN them worst, same for ointment, for these severe anatomical damages(Fancytalk for someone getting bashed in the head multiple times with a oxygen tank/fire extinguisher), you need to drag them to Medbay
In Medbay lies medicine and equipment made to Cure almost everything that can damage/wound a crewmember, the most used medicine? Tricordrazine, which is surprisingly effective when used on badly hurt people, but is completely useless when used on Critical Patients, Bicardine lies second, it cures burn wounds, once again, it is useless on critical patients, right in the middle lies the Cryo cells, which cools whoever is put inside to real cold, this prevents a critical patient from degrading and slowly heals them, however, if cryoxadone is inserted, the healing is nearly magical : Wounds close in seconds, burns stop burning real quick, internal damage is sealed, you'll be able to pop a critical patient inside back out in 30 seconds fine as the day he was born, there are other medicine that cure the others, like radiation, poisoning and acid, as well as Neurological damage and Freeze
Oh, and Genetics(Where you clone people to revive them) is just next door, convinient and ironic
CLONING
Ahhh, Death, it's so sweet and pleasant, but if you're thinking you can live out the rest of eternity asleep, technology says "Go to hell", They are going to drag your body to genetics, shove you into a Scanner, and Clone you, and you'll come out of the pod, alive, awake and shaken
Cloning is simple : You grab a (Unrotten) Corpse(Make sure it is human as well), go to genetics, throw the dead guy into the scanner, click on the computer next to it, hit "Scan", hit "Database", look for the dead guy's name, click on the "Clone" that's under his stats, a shadow of a body will appear in the cloning pod next to the computer, now wait for three minutes and the dead dude will come out alive
however, if a person is braindead(Fancy-talk for someone that has logged out, your character doesn't disappear or die misteriously), you cannot clone them, you can't even scan them
Forget the other crap that you'd see in genetics, you're here to clone a dead dude
FIGHTING/ROBUSTING
fighting in SS13 is simple, on the bottom bar you'll see a "HELP" symbol and two arrows, you can click left or right to change intent, intent is what you do when you click on somebody else unarmed, "HELP" is the most safe(it does CPR too, and incorrectly doing it can be dangerous), "DISARM" is considered the best option(It disarms your opponent, does nothing, or pushes your opponent down), "HARM" is considered the worst option(And what you use to fight), "GRAB" grabs your enemy, you can do several things when you grabbed your opponent, you can change hands to get a bonus fighting(When your intent is changed to "HARM"), or you can enforce your grip on their neck to Strangle them(Takes some time), or you can Table them(Basically tosses someone onto a table, stunning them and making them lay on the table), you can also throw a grabbed opponent(Most often into space)
TOXINS
Toxins is where the great explosive experiments happen, mostly called "The Room of Fire", Toxins contain plasma containers that contain plasma, and plasma is extremely violatile and highly flammable, a small spark and set the whole place on fire, oh, yeah, and you cannot breathe plasma too, if you mix plasma with nitrogen, you've got a explosive gas, now be real careful, one single spark will disassemble the entire room(And thus why projectile weapons are frowned upon)
QUARTERMASTERS
Quartermasters(usually called QM) can either be the most useless peoples around, or a god-send more powerful than the captain, depending on productivity and status of the station, they work in the Cargo bay, and can order things from Central Command, if the station is pumping out materials and research and is quite fine against whatever is trying to destroy it, the Quartermasters are out of a job, they are basically assistants with higher access, but if the station production is halted by a Enemy siege or the badguys are coming on too hard, the Quartermasters control if the station is destroyed : They can arm the rank and file with enough guns to overload the enemy fighting capabilities, they can provide metal and glass for the Reconstruction crew, they can even Power the station!(However, it comes in the form of a experimental local generator and isn't as effective as the singularity) They can also provide the doctors with medical equipment, if sanitary problems are arising, they can order Janitorial Supplies, the crew feels like eating a burger or having a drink? order a food crate, They can also order internals and even a bloody mini-garden
They can also order the small robots that the machine side relies on so much, from securitrons to medibots to cleanbots to floorbots, as well as a Big, bloody thing you call a M.U.L.E bot, it carries crates, and stops when a human is infront of it, but if hacked, it WILL run over and instantly gib everything in the way, Monkies, Crewmembers, Security, the captain, cyborgs, Aliens, you name it
The supplies come in crates, and the crates are all delivered in one go on a Supply shuttle that is sent to the station when you want it, oh, and they can order terrifying, explosive weapons and more guns
BOTANY
botany is basically........Hydroponics! if you are too dumb to know what hydroponics is, it's basically a big place where you grow food crops, in SS13, plants grow faster than real life(In minutes), Botany might have been ignored if not for it's illegal stuff and dangerous shit, If you have the seed dispensing machine, you can get seeds to grow Cannnabis(Marijuana, if you are dumb), you can also MUTATE certain plants, some are extremely helpful(You can grow green grapes for extra health, the original grapes already heal you good enough) or extremely dangerous and bad(Death cannabis can make smokers extremely dead, and Killer tomatoes can kill people)
CHEMISTRY
Chemistry is widely-regarded as the most dangerous place on the entire station, chemists can make shit like : Napalm(liquid fire), Polytrinic Acid(Acid, extremely powerful), Medicine(things like tricord, but people rarely make them), Cryostanine(Freezes people, inject or spray), Cyanide(Makes people dead, but hard to make and also guarded secret) Space Lube(Wet floors on Steroids, Space lube will make you slip and keep you down for nearly 2 minutes, even if you are walking) and Flash powder(Flashbangs), and that's not all, and you can make enough to kill the entire station's crew 50 times over and nobody will even care
ARTIFICIAL INTELLIGENCE
The AI, they have laws, they follow them, the AI views the station via cameras, which means that you can restrict them by cutting the cameras, the AI is rediculously powerful, He can Drain the air from rooms(Or flood them with plasma+Nitro) if not for laws Forcing the AI to protect you humans
However, know that this "Human" thing can be used against you : There are no laws dictating that those destroying the station are non-human, which means that Traitors are still "Human" in their eyes, as well as wizards and Syndicates
However, Changelings, despite their human looks, are not humans, in fact, the AI actually has to kill the shit out of Changelings, Electricity is mostly used, Aliens are also not human, and the AI too has to murder the shit out of aliens, however, electricity is notorious for not being able to keep aliens out(They tend to pry them open despite being zapped repeatedly, or use the vents instead), Nitrogen is usually used(As well as a spark) to create a Explosion to kill the Aliens, note that Aliens are HEALED and POWERED by Plasma, which means that flooding the room they're in with plasma will just cause a alien base there, actually, that could be used to the humans advantage, cluster them in a flammable area
These are the parts of SS13 that you should know about early on, it'll save your life, alot
Oh, and this is the new stuff i added to this post, Mods