I suggested some pattern drafting and draping books in a previous post ,but I failed to mention necessary tools. A few good rulers, a tape measure and some curved rulers are necessities.
I own a set of Fairgate rulers, plus a bunch of misc. ones.
I've also acquired some additional books because I went and looked and bought some after the last post...
I picked up a copy of The Practical Guide To Patternmaking For Fashion Designers: Menswear because I also am interested in sewing for Men. The suggested books at the bottom lured me in and I got Classic Tailoring Techniques: A Construction Guide for Men's Wear too, because I made a man's costume jacket once for a relative and had trouble with the construction. Menswear has different rules than womenswear, because suits are much more structured for men that women.
I also now own a copy of Donald McCunn's book How to Make Sewing Patterns. Mr. McCunn has a Yahoo! group dedicated to making patterns and makes himself, as well as many other talented individuals, available for answering questions. He is also offering online classes, I signed up for the first one, but became ill and was unable to participate. And things have been too busy around here to try another one this year. The concept of the first class was unique, we were to draft aprons for a wine bottle. It was a cost saving idea, a wine bottle is much cheaper to obtain than a 1/4 size dressform, yet still requires darts for proper fitting.