I found some marvelous free drawing books online in PDF format by Andrew Loomis. They've been a marvelous read and will be a massive help while I learn. I'll most likely be using them in conjunction with the Burne Hogarth books I've been reading, too. It's interesting to notice the difference between Burne Hogarth and Andrew Loomis: Hogarth focuses on the more technical aspects of drawing, detailing the exact muscle and skeletal structure beneath the skin, while Loomis focuses on the basics, allowing continued practice and experience do the work for him.