Steve B. (Quad Nut on the Kitebuilder.com forums) has provided an excellent document describing the basics behind drag and resistance, the airfoil shape and lift. Steve has done this in an effort to help us better understand how these fundamentals affect kite making. A document specifically dealing with how these ideas can be applied to kite making will be available soon.
This document is available in pdf format and will also be available as an HTML document in the near future.
Theory Behind Sailmaking.pdf enjoy!
Big thanks to Steve for taking the time to write this document.