Here are some links that is good to know:

Clanbase, a good site with mutch clans and leagues.

Planethalflife, a site with mutch news and modifications to Halflife

Barrysworld, Here can you borrow servers for matches or for a trainings.

Firearmsmod, The official firearms mod clanpage.

mIRC.com, Here can you download the program you need to talk with us on irc (#nuked @ quakenet)