I have a book called "Portfolio Presentation for fashion designers" by Linda Tain that I'm using right now to help me get my portfolio together. Also you may try getting a book on flat pattern. An old one would be fine since it hasn't really changed. The one I lerned from is by Norma R. Hollen and it's an old copy from the 80's. As far as fashion illlustration, I love "fashion illustration next".