Autism Speaks, the national organziation founded to provide parents, educators, and medical professionals (and anyone else interested), has put together a new resource.
The web site offers dozens of video clips of children with autism and contrasts the behaviors with other children who do not have autism. The site also defines terms and behaviors.

Autism Speaks, Press Updates, Autism Speaks Joins Florida State University and First Signs in Launching First-Ever Web-Based Autism Video Glossary