I know this post is years old, but James Munton has a great DVD on how to teach a magic class. It's got some great ideas of tricks he uses to teach birthday party magic classes.
Mr. Greggy's Instant Author book has great reviews on some other forums and looks to be a bargain.
I also recommend my instant author kit - a great resource not only for BOR sales, but teaching magic classes, or as giveaways (http://www.PrestoMagicProducts.com
I highly recommend avoiding some of the more popular "101 magic tricks..." type books that often feature dangerous and outdated props. There are a lot of them floating around! Even though some of those comes cheap from places like D. Robbins, they're out-dated, and I believe you could actually get in trouble distributing materials that advocate the use of knives, cigarettes, etc.