You first need a client in order to download torrent files. I use Azureus.
You can start on TorrentBox. It is a good general site that has been up the longest of any sites that I have used. The global search feature (searches ISOHunt for you) exponentially increases your pool of files.
Here are some others I have had luck with:
http://bt.etree.org/ <- Great for live music – do a search
http://www.fulldls.com/ <- This one is hit or miss with the files
listed, but it is a good source
http://www.podtropolis.com/ – downloads already in iPod format!
And from each of these, you’ll find more links to more sites….
CAVEAT: Make sure you have antivirus on your system and that you
update the definitions DAILY.
This should cover you…..you may want to additionally get an
antispyware client…tons of free ones out there, all are ok, none are
clearly the “best”….i’d go with “Spybot Search & Destroy”
None of this stuff is necessary, but I’d highly recommend having these
3 elements of protection on you system this day in age. Not even for
Bit Torrent, just general protection…..