Go here:

http://www.emule-project.net/home/perl/general.cgi?l=1

Download Emule. It's free and no spyware. Pretty easy to use. Just make sure you have a port open in your Windows XP firewall if you use it. As far as IRC goes, I've never been able to figure out how the hell to use IRC to download files so good luck with that. I still doubt that you'll find 200 UFC movies on IRC like you find on P2P network.