I finally picked up my Codebook today! Previously the only source I've known about was Brown Bookstore in Houston, but Barnes and Noble carries them:
http://search.barnesandnoble.com/King-Solomon-and-His-Followers-25/G-A-Gavitt/e/9780880532594/?itm=2
You can actually see if a store near you has them in stock. If they do, you can have them hold a copy at the cash register. It's a little challenging to figure out what you're looking at. I have a pretty easy time on the Q&As, but the other stuff I have to think about and fill in the missing pieces.
http://search.barnesandnoble.com/King-Solomon-and-His-Followers-25/G-A-Gavitt/e/9780880532594/?itm=2
You can actually see if a store near you has them in stock. If they do, you can have them hold a copy at the cash register. It's a little challenging to figure out what you're looking at. I have a pretty easy time on the Q&As, but the other stuff I have to think about and fill in the missing pieces.