I am always looking for new sites and blogs. This one was posted on Publish-L and starts with a great article on bar codes:
For anyone looking for someone to design their cover, Book Cover Express designs book covers!
They also have several links for publishers, including one to a book on Amazon called "Bookmaking: Editing, Design, Production, Third Edition". (And on that page are numerous other books on publishing!)
So go check it all out!!!