There is so much slang and so many abbreviations in the world of warcraft anyone would be forgiven for thinking the game had its own language! While there are actually other languages in the game, we're not going to go there in this guide, for the most part you will see what is spoken in plain English.
WoW = World of warcraft - copyright blizzard entertainment! <3
AFK = Away from keyboard
BRB = Be right back
LOL = Laughing out loud
ROFL = Rolling on the floor laughing
MT = Mistell (if a player sends you a tell meant for someone else for example)
LFG = Looking for group
LF1M = Looking for 1 more (sometimes they will be LF2M.. looking for 2 more etc)
NPC = Non player character (like a vendor or a monster)
Mob = An NPC, usually a bad thing that you are trying to kill or going to kill
Proc = short for Programmed Random Occurrence, eg; describing a weapon/trinkets chance on hit
DoT = damage over time (a spell that you cast, then it continues to damage its target for a set amount of time
DPS = Damage per second
Char = Character, sometimes called a toon.
OOM = Out of mana, if a healer says this, wait til they get mana back before you do anything else!
WTB = wanting to buy
WTS = wanting to sell
Noob = Newb or newbie, someone who is new! (or they're calling you an idiot...)
Nerf = When something becomes not as good as it used to be for whatever reason.
WTF = what the %$#&
FTW = For the win!
W00t = yay... basically
IMO = In my opinion
PST = please send tell
PVP = Player vs player
PVE = Player vs environment
Ninja = Someone who takes an item when they shouldn't.
Mats = Materials (usually in reference to items need to craft)
Chat channels are split into areas, for example, the area you start in as a human is called Elwynn forest, you will probably notice people talking and maybe you want to add something or ask a question, don't just press enter and start typing like i did! That will limit your conversation to 'say' and will only be heard by those who are near to your character.