The sticky at the top of the RCUniverse Aerodynamics Forum provides a list of the best and most economical books on the subject. http://www.rcuniverse.com/forum/m_9346279/tm.htm

The topic takes a book to explain. It ain't sound byte simple. It actually takes a couple of books. The ones listed in that thread happen to be listed in order of "efficiency". The first couple are affordable and written so the average modeler can understand. That list is your answer.