This is the best tool I have seen for calculating CFD position sizes and CFD risk management of trading systems.

I cannot recommend an author above Dr Van Tharp. Van has a PH.D. in Psychology, was on the panel selecting people for the famous 'Turtles Trading',  featured in Jack Schwager's, The 'Market Wizards', is an author of several books himself, trading coach to some of the worlds largest floor traders and institutions and oh, he has been doing this since 1982 (26 years). No body knows more about money management than this man. Check out the link for more information and a list of his books.

LearnCFDs.com

This is a relatively new site that list a host of general information on trading CFDs, some fun stuff, Trading Quotes and a host of well thought through CFD trading material.

ClickBank

For internet marketers looking to promote the CFD Survival Guide to their valued clients.