Write to your state officials.
Write to your representative  and ask him/her to ban animal racing. If you live in a state that has greyhound racetracks, tell your state representatives to ban dog racing.
Ask your representatives to co-sponsor the Interstate Horseracing Improvement Act 
Create a paper petition to send to your state representative.
Here's a guide  to walk you through it.
Create an animal rights club in your school.
Your DoSomething.org club  could focus on the problem of animal racing and other issues.