What is a good diet, nutrition book?

I need to start new and better eating habits. I'm taking on a low-carb. diet but I need some guidance. I checked out "Eating by Design" by Carrie Latt Wiatt and it seems good but I was wondering if there were any other good ones. Tony Horton has one out but I read a few reviews and a lot of them said the book was full of stuff from his blog and they didn't really gain any "new" material to work with. Any ideas?