Seed to Seed by Suzanne Ashworth - seed saving and growing techniques for vegetable gardeners. An excellent reference book with regional growing recommendations.
The Bread Bible by Rose Levy Beranbaum - many excellent recipes! Rose also explains the science of breadmaking and includes a wealth of information and resources. I would recommend any of her other "bibles" as well. I also have her Pie and Pastry Bible and until I read that one, pie crusts were one of the things I just could not do.
@Eric_2: THANK YOU for the link to the free PDF download! I'm working on a PDF library and some of those books will be added to it. Tip of the hat to you, sir!