i've found what works best for me is, in firefox, get an addon called magnetiser, then use www.torrentz.com to search for the file you're looking for. when you find the best option, select
that one, and then instead of choosing from a list of sites to get the torrent from, click
magnetiser and it will aggregate all the trackers and create the torrent (or something like a magnet
url) itself without leaving torrentz.com, and without risking any spyware from any unsafe sites.