PBS hosts a series called "In the Mix", focusing on teen issues.  On the site, you will find links to videos on a variety of topics, some of which are focused on peer mediation and conflict resolution.

http://www.pbs.org/inthemix/educators_index.html

Further, below is the link to a lesson plan on "A Primer on Peer Mediation" which coincides with the In the Mix Episode "School Violence: Answers from the Inside".  The lesson plan provides links to the video.

http://www.pbs.org/inthemix/educators/lessons/schoolviol1/index.html