From my own bookmarks *grin*
http://eq2.zam.com/ Quests and miscellania information about the game.
http://eq2.eqtraders.com/ Tradeskills, furniture/decorating, and whatever pertains to those.
http://www.everseek.com/ and http://eq2decorators.com/index.html for house items and decorating with http://www.eq2designers.com/ as the home of the infamous.. err wonderfully lovely housing layout editor (that is too addicting beyond words).
http://www.eq2interface.com/ for UI modifications (not like the WoW ones which, I have heard, practically play the game for you, but ones which make the game more playable for those who don't care for the default UI).
http://adornments.h0b0.net/ for stellar information on adornments.
http://www.beetny.com/eq2aa/ for an AA calculator.
And... if you don't mind the level or profanity (and outright hostility) of a flame-based site, EQ2flames.com (can't link because of it's non-PG13 content) does have some excellent information for various classes at the top end. Many of their regulars who moderate the class forums there are knowledgable but tend to impart that knowledge with a judicious dollop of R to X rated material. The site is definately Not Safe For Work viewing since you never know when someone will slip in an image of.. well.. something which could get you fired.