Search Headquarters : Games : Video Games : Shooter : T : Team Fortress Series : Team Fortress 2 : Modifications and Add-Ons

FPS Banana: Team Fortress 2
Information and downloads for custom maps, skins, sprays and scripts.
http://www.fpsbanana.com/games/297

TF2 Dev
Signature generator, map of the week, videos, and forums.
http://tf2dev.com/

TF2 Sprays
Custom logos and sprays.
http://tf2sprays.com/

TF2Maps.net
Forums, and downloads for maps, models, textures, and tutorials.
http://tf2maps.net/

Toy Soldiers
Map pack and modification. Includes information, files, and forum.
http://toysoldiers.olddrunkenbastards.com/

Valve Developer Community - Team Fortress 2
Official collaboratively edited site that provides tutorial for making maps and modifications.
http://developer.valvesoftware.com/wiki/Team_Fortress_2