How you can convert a file into a torrent?

Open your Bittorrent client (eg. Utorrent, Azerus, Bittorent) and go to:

File > Create Torrent.
2. Select the files and or directories 3. Trackers: Below are some popular public trackers. They are servers which help peers to communicate.
Here are some good trackers you can use:
http://open.tracker.thepiratebay.org/announce
http://www.torrent-downloads.to:2710/announce
http://denis.stalker.h3q.com:6969/announce
udp://denis.stalker.h3q.com:6969/announce
http://www.sumotracker.com/announce