Documentaries

 The Research and Training Center on Community Living sells videos suitable for showing to groups.

http://www.diversityshop.com/store/product2.html
http://www.selfadvocacy.com/Tools_for_Change.htm
 
Definitely visit their web site at http://rtc.umn.edu/rtcmedia/
which has among other good things a slideshow giving a history of disability.