Banning Guidelines

Rules for the Banner
If you're about to ban someone, make sure that you've followed the guidelines below first:
 * Give the User a second chance
 * Make sure that the User understood what he/she was doing wrong
 * Told him/her to stop
 * Consulted with the other Admins about him/her (not always necessary if you need to ban them right now or else they'll cause more damage)

If you've done all those, and he/she won't stop, then you can go ahead and ban them. Depending on what they did, Give them a reasonable ban time! For permanent bans, consult Lokilog or Tybug2.

Rules for the Banned
If you think you've been banned unfairly, then go to the admin that banned you (at Community Central, as you're banned from this wiki), and leave a message on their blog or Message Wall. If the Admin who banned you won't cooperate, or says no (which is likely to happen) then you can try to take the problem to other Admins. However, DON'T take this problem to other wikis. You don't want to annoy even more Admins on those wikis. If the answer is still no, then you'll just have to wait for you're ban time to expire. If it's permanent, then what in the world were you doing in the first place to deserve a permanent ban?!

Helpful Articles
If this isn't enough information, Community Central has pages written specifically for this, as they have for a host of other issues:

http://community.wikia.com/wiki/Help:Blocking and http://community.wikia.com/wiki/User_blog:Sannse/How_to_Get_Unblocked <---(I recommend this one.)