FreeCulture.org has an IRC channel at #freeculture on irc.freenode.net
Learn how to join Free Culture's IRC channel using gaim.
Here a tutorial about how to use IRC with irssi and screen.
If you use MacOSX, read a tutorial for installing and using Colloquy. When it says to join #adium, join #freeculture instead.
There's also an extension for Firefox called Chatzilla
If your school attempts to block IRC, there are ways around an IRC block.
Our friends at Yossman have setup a web based irc portal from which you can access #freeculture. In the first field erase yossnet08 and type in your name with no spaces, on the second one erase #wikipedia and put in #freeculture now press the login button.