addons - curse.com, www.wowinterface.com/
armory - www.wowarmory.us/
class mechanic guides (general) - icy-veins, max.dps, noxxic.com
class mechanic guides (complex) - elitistjerks.com
character database - www.wow-heroes.com
guild- player ranking - www.wowprogress.com/
lore/general guide - wowwiki.com, wowhead.com

* Icy-veins has a calculator application called Ask Mr. Robot that will help you maximize your armor potentials according to builds

This post has been edited by areix: Feb 13 2013, 02:54 PM