I bought this book a while back because we found that we were buying and tasting so much wine that we thought we should educate ourselves a little bit. It was not actually the first book we bought for this purpose, but the first book assumed that you were familiar with French wines, and we weren't, so we picked this guy up.
It makes a good bathroom read. It does not provide any real details on the differences between different AVA's or even varietals; but it does introduce some terminology and practices that should be useful to a newbie.
It was especially good at explaining why the French systems are in place, and what they really mean, and why you should care that a grape is a Bordeaux varietal or not.
What I did not like about it was it's winery recommendations. Each chapter had a recommended producer list associated with it, and they were all the supermarket wine producers (but then again; what can you expect from a book endorsed by Robert Mondavi himself)
The Verdict:
If you read my posts and don't know what I'm talking about, then it's a good buy. If you do know what i'm talking about, then it could still be an interesting browse.