Ok, trying to gather all sites into one post, please comment and add more:
http://www.worldofraids.com/ best PvE site, lots of fresh info
http://wow.curse.com/
http://www.wowinterface.com/community.php
http://www.worldofwar.net/?p=home
http://www.wowace.com
http://files.wowace.com
http://www.lootables.com/
http://www.wowhead.com/
http://www.wowdb.com/
http://www.thottbot.com
http://www.allakhazam.com
http://gathereraddon.com/
http://auctioneeraddon.com/
http://www.ctmod.net/
http://www.blizzplanet.com/
http://wowvault.ign.com/
http://www.goblinworkshop.com/
http://wow.azzor.com/
http://www.tentonhammer.com/wow
http://www.bosskillers.com/
I will try to sort them later.