Firearms section on ModDB. Probably the only resource that is alive these days...
Marine Bot (a bot for Firearms mod) homepage.
[APG] = All Platform Gaming - a forum having various rare downloads for Firearms.
An official Firearms website. You can track Firearms developing process there.
Another award-winning website about the best half-life mod. Lots of maps!!! Also you can get any FA version here.
Lots of models and modeling tutorials here.
Our favourite ISP's Firearms resource supporting popular game server.
Excellent gaming forum.