A major difference is that Limewire uses only the Gnutella network; torrents are all over the internet.

I still use LW for music, but I get my movies via torrents. LW will dl a few torrents for you, and that would be a good start. However, after you get your feet wet, you really should use a true torrent client, such as Vuze or uTorrent (both are free).

Good info here: Beginners Guide to torrents.