Major resources

rec.games.roguelike.angband

The Angband Newsgroup. Lots of friendly people. You may post character dumps there and ask for and offer advice.

http://rephial.org/

The current home of Angband development - including bug tracking systems and downloads, user manual wiki, etc..

http://angband.oook.cz/: The major Angband website, including news, discussion, information, and various nifty utilities. Go to the Ladder to see the top scores for many variants of Angband. Includes:

http://angband.oook.cz/forum/

Discussion forums to complement the newsgroup - another place for discussion and advice.

Minor resources

http://ftp.sunet.se/pub/games/Angband/

The largest repository of Angband files (somewhat dated)

Thangorodrim

The official Angband site prior to rephial.org; although now dormant, it is still live, and is the largest clearinghouse of Angband and Angband variant information on the Internet. Has more than enough links to keep you busy.

http://ajps.mine.nu/angband/code

Put a code on the bottom of your posts that describes exactly how you play Angband. Lots of fun.

http://www.mirc.com/

If you like interactive chat, there is a channel dedicated to Angband. Go to this link, download mirc, and use it to connect to one of the WorldIRC servers (note: you do have to use a worldirc server). Then join the channel #angband. You'll know you've got it right when you see other people (the channel is always occupied).