In Defense of Food (Michael Pollan)
What to Eat (Marion Nestle)
I am not sure these could be considered instructional or how-to books, but they are very informative and fascinating in terms of how we eat, what we eat, and how we fall prey to marketing, food addictions, etc. In that vein, I found them very motivational:
The End of Overeating (David Kessler)
Mindless Eating (Brian Wansink)
"If you drop an egg, you don't say, 'Oh, shoot' and drop the other 11, do you?"
-Source unknown, but obviously brilliant
Reached goal 4/16/2010...but kind of afraid to look these days