Not a bad book for beginners, with the major areas you'd expect (driving technique, racing line, etc) covered, even if some of the detail is a little on the light side at times.
Great use of colour photographs throughout, too, although diagrams (for racing/defensive/etc lines) are a little scarce. Still, there's some good tips throughout, which is a nice touch.
My main issue, however, is that by being a US-based book it means that a quite a lot of the information isn't relevant to UK/European karters, which feels like a waste. Not a fault of the book itself, of course, but worth bearing in mind if you're not planning to race in North America. (If you are, then add another star to my rating!)
Not a bad effort at all, then, but there are better, more detailed, more comprehensive and more UK-focused publications around.