You WILL go to this site and buy the book!
http://www.doublesdistributors.com/
I work NCAA rules, and the Referee's Study Guide they make for NCAA rules is excellent. But they also have one for NFHS, and if it is as good as the NCAA version, then it's a must buy.
Don't know how updated the above website is, but you can also get it from here:
http://www.honigs.com/browse_products.asp?Cat=2&Sub=33