The IRC is #bsdcert on freenode.
A quick tutorial on using GAIM for IRC is at http://www.kplug.org/ircchatsetup/gaim-irc/index.html. (For the server I used "irc.freenode.net". Be sure to use #bsdcert as the channel. It might also be useful to Enable Logging under the Options menu.)
Some more examples for various clients are at http://gc.stonewallcs.com/IRC/clients/.