Andrew Weil is one of the foremost experts on nutrition. The Beginner's Guide to Healthy Eating provides a great start for individuals looking to learn more about how what they eat will affect how they feel. If you've studied nutrition in-depth, a lot of what Weil says might be new to you (e.g. think of this book as Nutrition 101). Having said that, I think just about everybody will get something out of this title.
One of things I like best about Weil's theories on diet is that they seem very sound. He bases a lot of his opinions on study of the traditional Japanese and Mediterranean diets, diets that have proven to be very healthy and helped to increase longevity in their adherents. In addition, he doesn't take an unrealistic view towards nutrition. He doesn't expect individuals to spend all day in their kitchens or to purchase all sorts of expensive and exotic ingredients. Instead, he favors simplicity in diet and food preparation.
The only knock that I would have on this title is that it doesn't go into depth in a lot of areas. If you're looking for a more comprehensive view of Weil's nutritional advice, check out his audiobook Eating Well for Optimum Health. However, if you're new to the world of nutrition and looking for an introduction to Weil or for a relatively simple and healthy diet to follow, The Beginner's Guide to Healthy Eating will be perfect for you.