"How to Draw Comics the Marvel Way" is probably the chief book I learned to draw from - It's excellent.
Other books you should take a look at/buy:
The Jack Hamm series, although dated in its content, is a must have - "Drawing the Head & Figure", "How to Draw Animals", and "Drawing Scenery: Landscapes and Seascapes".
Burne Hogarth's "Dynamic Anatomy" is a staple. Hogarth has other books out there, but this one is the best.
"Drawing Dynamic Comics" by Andy Smith is a more recent book that is as good as, if not better than, the Marvel book.
There are others of course, but these books seem to cut to the chase in a very simple yet professional manner. Don't forget to grab books on perspective and composition too - those are always handy.
Cheers!