You will need:

1. Bittorrent client software (there are dozens of choices, all free to install).

2. A Torrent search engine that helps you find .torrent text files (TorrentFreak.com's top 10).

3. A .torrent text file that points to the movie/song/file you want to download.

4. An Internet connection that has a port (usually 6881) opened (on your router) to allow Bittorrent traffic to pass through.

5. A working understanding of file management on your PC/Mac (you will need to navigate many folders and filenames to make file sharing work for you).