This is one of my favorite books for beginners. I use it in my classes a lot. Most of the exercises and principles are the same ones you'd get out of a book like Drawing on the Right Side of the Brain (another favorite of mine), but I've found this one easier reading and more confidence-building for a lot of my students, with a very welcoming and soothing quality.
If you've always wondered whether you could learn to draw, this book believably shows how you can. Highly recommended. It's on Amazon here.