UPDATE: Drawing Realistic Textures in Pencil, by J.D. Hillberry – a book review from Oil Pastels by Mary – http://wp.me/p2Dxvf-14V use the code MARY to get 20% off this excellent book!
Although I work primarily with watercolors, and Mary with oil pastels, I agree that this book is very useful in learning which textures and light qualities convey realism. Many thanks to the artist-author J.D. Hillberry.