"The Lord of Murder shall perish, but in his death he will spawn a score of mortal progeny.
Chaos shall be sown in their footsteps".

Biowares Official Site
Keep up to date with the latest goings on at the developers of the Baldurs Gate series official site, who knows, perhaps you'll even be the first to see mention of a BG3 ????
Biowares Official BG2 Series Forums

Shadowkeeper
A fantastic program, with this you'll be able to edit virtually any part of your character and your NPC friends.
Infinity Explorer
Explore the game in the minutest detail with this program, special abilities, characters, spells, items and more.
Baldurdash
Popular BG2 site that has plenty of fixes for all the things in BG2 that just didn't work right.
Near Infinity
Near Infinity is a combined browser and editor for games based on BioWare's Infinity Engine. It supports both Baldur's Gate 1 & 2, Icewind Dale 1 & 2 and Planescape: Torment as well as the official expansion packs. Limited support for Neverwinter Nights is also included.
Pocket Plane Group
Modding community for BG1 and BG2, has lots of custom mods and seems to be well supported.
Weimer's BG2 Mods
Lots of mods for BG2.
The Gibberlings 3
Infinity Engine Modding community.
SpellHold Studios
More BG2 modding goodness.

Baldurs Gate 2 Portrait Portal
This is THE sexiest Baldur's Gate 2 Site I have ever seen and filled with original portraits that you won't find anywhere else, check it out.
BG2 Portrait City
The largest archive of portraits I have ever found, they have 5,000 male and female portraits of various races ready to browse and download.
Arundor's Abode
This site is filled with custom creatures, spells and items for BG1 and BG2
Kirith's Portraits
Large collection of portraits covering all races, genders and classes.
Baldurs Gate Treasures
A very creative webmaster with original content and themes along with soundsets from the games, well worth a look but you'll need a fileplanet / gamespy account to download anything. I think it's still free though.