This book is basically an abridged version of the character sheets used on the Simpsons show, with a few extra notes inserted, so there isn't much to actually read. The foward by Matt Groening is amusing and has some useful pearls of wisdom buried in it for the budding cartoonist.
The tips given in the book are very good and are a boost to anyone wanting to draw Sinpsons characters, or indeed any cartoon characters as a lot of the tricks and tips can be applied to forms other than yellow people with freakish overbites.
The only real critism I have of this book is that it is too short and scimps on some important areas like body language, prop drawing, construction of hands and the like. The content which is there is very good, there just needs to be more of it.