I highly recommend uTorrent for downloading torrents. Its simple, its easy and its an EXE file so it never "installs" on your PC. 1 icon you click and it opens each time without ever installing onto your PC. When you run it for the 1st time, it will ask if you want to make it your DEFAULT program for torrents and you want to choose YES. From there its a piece of cake whenever you download a torrent.

http://www.utorrent.com/


And for downloading torrent files, I recommend these sites in the order in which I placed them:
  1. http://isohunt.com/
  2. http://www.novatina.com/
  3. http://www.torrentupdates.com/ for your up-to-the-hour latest torrent additions.
But I tend to find anything and everything I need just with ISOHUNT.