This site provides an explanation of the behaviors most commonly associated with bullying. It offers several helpful additional sites. "Stop Bullying Now!" (at the bottom of the site), offers flash movies, games, and information about bullying and how to prevent it.
This helpful site for parents opens with a flashing presentation that provides an insightful description and examples of cyber bullying--worth watching! You can then click "skip this intro" to access more information on topics such as how to prevent it and how to take action.