I have the following 'self help' art books, and speak highly of ALL (if you can find them, get them:

JACK HAMM:

Drawing the Head & Figure (ISBN 0-399-50791-4) also published as How to Draw the Figure from Head to Toe (ISBN 0-7740-3533-1)
How to draw Scenery (ISBN 0-744-3531-1)
How to Draw Animals (ISBN 0-399-50802-3)

J Peffer
DRAGONART How to Draw Fantastic Dragons and Fantasy Creatures (ISBN 1-58180-657-4)

CHRISTOPHER HART
Drawing Cutting Edge Comics (0-8230-2397-4)
Drawing Cutting Edge Anatomy (0-8230-2398-2)

ANDREW LOOMIS
Drawing the Head and Hands (0670283851)