I visited the Hershey, Pennsylvania public library this weekend. It was begun, like everything in Hershey, by Milton Hershey, the chocolate industrialist, and this reminded me that I've always wanted to read Hershey by Michael D'Antonio. The problem is, I tend to stick it on a book display whenever I remember it, and because the cover of the book looks like a Hershey chocolate bar, it gets checked out immediately. I think the same principle (but with cupcakes instead of chocolate bars) sells a lot of magazines at the grocery store.
On the subject of chocolate, we also have a new book, Jacques Torres' a Year in Chocolate, in which the pastry chef and chocolatier outlines recipes for holidays and seasons, and the Ghirardelli Chocolate Cookbook from 2007.
If history is more to your liking, there's the microhistory Chocolate: a Bittersweet Saga of Dark and Light by Mort Rosenblum or the corporate history of the Hershey and Mars corporations, The Emperors of Chocolate by Joel Glenn Brenner.