I bought this book last year, and it's really one of the great ones. However, I don't think it's appropriate for someone who's looking for a "how to draw" book. If you are a beginner, I'd reccomend a good artist's atlas or an art class...
Mr. Hart is not trying to teach you how to draw his characters, but how to perfect your own. I think most of the beginning is just filler; It's weak on form and the instructions are a little confusing. HOWEVER, it's chock full'o goodness in the form of tiny details that a beginner might be unfamiliar with; The fact that a woman's high heeled shoe sticks out at the heel, How the tilt of a nose can change personality, etc.
I have yet to see a better chapter on perspective. Although he does have the obligatory "This a box, these are the box's disapearing lines, etc", he goes much farther, showing how to place a character in relation to the horizon without having to use three rulers and a protractor. Very concise and easy to understand. If you're past stick figures but not quite happy with what you produce, this may be the book for you.
It should be called "Cartooning for the Intermediate" :)