lets get something clear, what can and can't get you banned, its kinda... annoying knowing that half your community thinks you can get banned for reading and following a gold guide... or other things like this... its kinda ridiculous actually...
you can get banned for SCAMMING...
you can get baned for BOTTING (using a bot of any kind, follows the same idea as the next one)
if blizzard decides to you can get banned for USING AUTO CLICKERS OR BUILT IN KEYBOARD MACRO PROGRAMS (if you use them like a bot to play the game for you)
you can get banned for HACKING (using a 3rd party program of some sort to cheat)
you can get banned for EXPLOITING (using bugs in the game to gain an unfair advantage over other players)
you can get banned for MODEL CHANGING (if you are unlucky and someone reports you for like...floating in the air or getting past doors you aren't supposed to or blizzard starts REALLY scanning and banning for this stuff)
you cannot get banned for READING AND FOLLOWING A GOLD GUIDE (provided it does not require the use of any of the above thing)
you cannot get banned for READING AND FOLLOWING A LEVELING GUIDE (provided it does not require the use of any of the above thing)
you cannot get banned for USING AN ADDON (addons that go in the interface/addons directory, unless they somehow allow you to talk to the opposite faction or play the game for you)
you cannot get banned (that I know of) for going to mmowned while playing WoW (I'm not 100% sure in either direction about this, but I seriously doubt you can)
thats all I can think of, feel free to add your own.