I just have to mention this awesome book that I just read that I am reading for next month's book club. Food Rules by Michael Pollan. It can be seen here on amazon.com.
It is great, and seriously only takes 30-60 minutes to read. It basically sums up a lot of what I tell my clients about developing a healthy relationship with food, what to watch out for, and basically just common sense about food/dieting.
I also highly recommend two other books Pollan has written: In Defense of Food and Omnivore's Dilemma which have both changed my understanding of food and my relationship to eating forever (in a good way!). But those books are a lot more detailed and dense. If you aren't a reader--see the movie Food, Inc. and it covers a lot of the material as well.
So if you want to start easy/common sense of just the basics of how/what to eat--read Food Rules. Then if you need some more explanation, go to In Defense of Food. And if you become consumed like I did--then read Omnivore's Dilemma.
In health and wellness,