It is very easy to use. D/L a BitTorrent program. (I use BitTornado). Run the application file or whatever to install it onto your PC.
Go into the Announce section on QZ (or use another site like Mininova.org) and click on the Torrent file.
Either save the file (for future ref) or open it straight up. Go to the folder that you want to save the file into and click on save. It should now start downloading. Sometimes they can take a little while to start to get going. QZ is actually quite good with a quick speed starting straight away. If you stop downloading before the file is complete, you can re-start the d/l without losing any data. If the Torrent cleint is set up correctly, it should re-start automatically. If not make sure you go to save it in the same place as last time.
Death to Rapidshare. Long Live BitTorrent!!