The greatest horse race is occuring this weekend on May 3rd, the 134th Kentucky Derby also known as "The Run for the Roses". This would be a great time to discuss the history of horse racing in your class. Here are some websites that might be helpful when preparing for this lesson:
http://www.kentuckyderby.com/2008/ The Kentucky Derby Official Website-history, information on all of this year's horses, etc.
http://www.derbymuseum.org/ The Kentucky Derby Museum
http://www.horsehats.com/jockey-silks.html This site allows you to design your own jockey silks online
http://www.derbypost.com/pastwinners.html List of Past KY Derby Winners until 2006
http://www.derbymuseum.org/derbyedu/programs_online/ This has activities for 4-12 grade with science, math, reading integration
There is so much that you can do with this lesson whether it deals with genetics of the horses, race track composition, nutrition and training and the list goes on.
The website listed above do have information related to horse betting therefore you may experience trouble accessing them at your school.
Please share what you are doing in class as it relates to the Derby by posting a comment so that we can share ideas.