Try Athletic Rules Study: Get the 2003 high school football rules CD. The 2004 CD will be ready around July. They have the last 5 years of NFHS tests, that you can answer true or false and then get the result right there, with the complete rules, case and illustrated books cross-referenced.
Its well worth the 30 clams they charge for it.
Go to the following website:
http://www.rules-study.com
or type Athletic Rules Study in your Google or search engine.