The most important thing you could tell a child or a teen that is being bullied is that they are not alone and it is NOT their fault. Most often those that bully have an issue at home or with themselves and in an effort to make sure that those around them feel some of their suffering they bully those around them.
It is also Important to make sure that everyone knows that there is help out there and promote talking with your kids. And kids don't be afraid to talk to your parents. The odds are in your favor that they probably have dealt with bullies at one point in their life too. Bullying is all about fear and power. Don't be afraid, and speak up! Don't let another person hold more power over you than you have over yourself.
Violence Prevention Works website is an all around good site to go to for information. We have included a couple of their links just to get you started.