I would recommend you use a torrent site such as thepiratebay, mininova, torrentz, etc.
They all contain the same stuff, really, but they present it in a far more useful way, showing you seeders, leechers, health of the torrent, and so on.
It's much better than using Google, and you can search for whatever you want and only get torrents.
Also, google recently started to block all .torrent searches. Check out the article in my source. Soon this will not be possible.
However, if you were searching for torrents of kittens, for example, you would have done this:
kittens filetype:torrent
Edit: Just a quick note, what GiGi said is wrong and doesn't work.