So, basically, it's like other p2p software, but the technique is superior in some hazy way I won't bother to look up, so you use it for big files.
You start by downloading a .torrent file, which you can search for at bittorrent.com, thepiratebay.org and a whole shitload of other places.
You then open the file with whatever application you have, and, presuming your firewall isn't being a shit, you can download whatever huge file the .torrent points to relatively fast.
More seeders = good.
Presumably you're using the client you can download from the official site?