The Compleat Taildragger Pilot
I read this book prior to obtaining a tailwheel endorsement. I felt the material was exemplary and reflected relevant aspects of tailwheel flying gleaned by the author over many years of tailwheel flying experience. I plan on re-reading the book now that I have a tailwheel endorsement and expect to gain an improving level of knowledge on the topic.
Great book. Lots of good information. Great section for CFI's planning on giving tailwheel endorsements.