It seems very few articles introduce what should be done. I'll write down some notes here for reference. Key services should be set up is "Tracker".
You can have a look at the following links for more information about what tracker is:
I use "xbt"(http://xbtt.sourceforge.net/) as my tracker software on CentOS 5.5 (Clone of RHEL 5.5).
Install xbt as http://xbtt.sourceforge.net/tracker/. But you should notice that the latest xbt software from SVN can't be compiled on CentOS 5.5 because of boost (1.33.1 on CentOS 5.5).
So, you should change to the following commands if you are not going to update your boost library:
svn co -r 2010 https://xbtt.svn.sourceforge.net/svnroot/xbtt/trunk/xbt/misc xbt/misc svn co -r 2010 https://xbtt.svn.sourceforge.net/svnroot/xbtt/trunk/xbt/Tracker xbt/Tracker
Remember to create "xbt" user and "xbt" database, and tables in xbt_tracker.sql before you run xbt. If you are not going to update database with code or manually, you'd better set "auto_register" to 1 in xbt_tracker.conf. So that the tracker service can be supplied for any client connects to the server.
What you should do next is to make torrents using your own tracker URL as tracker information. And then use your favorite BitTorrent client software to seed your files. "transmission" is very easy to use.
(Notes: The above article updates boost library by himself. So he can use the latest xbt.)