I'm very impressed with the new ArtRage version 3. It is very powerful, have many of the features of more expensive drawing/painting software, its fast and easy to use.
Drawing from Burne Hogarths Dynamic Figure Drawing. His other books include: Dynamic Anatomy, Drawing the Human Head, Drawing Dynamic Hands and Dynamic Light and Shade.
If you would like to learn the ArtRage the easy way. watch the video tutorials by Judith Tramayne on her YouTube Channel http://www.youtube.com/user/JudithTramayne .