You can pick from many cities to download games. From mininova, pirate bay, and demonoid. The main thing to do before downloading is read the comments below each torrent. People will warn you if there are virisus and such.
Bittorent is just the client to download the files. to get the downloads I recommend "thepiratebay.org" I get movies, games, programs, etc, from it all free. but for a downlaod client, instead of Bittorent, I use Utorent. Seems to work better for me. good luck!
To be honest, its not that reliable for games. I tried to download Battlefield 2. That was a massive mistake. I got a virus that was really hard to get rid of. I actually had to re-install windows along with the video drivers, the sound drivers etc. Anyway, the reason why you don't want to download full games off there is because there are so many different folders to hide a virus in and they are really hard to find. Bit-torrents are ok for downloading movies because you can see that you are only downloading the Mpeg file. So if i were you, i wouldn't trust it for games.