Great article about how books are made from the New York Times. If you ever wanted to see the process follow the link below:
Me (Olly) and Rich have both worked for printers in the past, before we set up on our own with More Visual. The printers we used to work at only printed the cover artwork, which was then sent out to the book binders to be finished off. The company eventually liquidated and we set up on our own concentrating on graphics and specialising in book cover design.