In Digitizing Your Photos I show how to export directly to a Blurb book from Lightroom’s book module. Here are some other services you can use to make custom books.
A&I Lab in Los Angeles makes some absolutely beautiful books in multiple formats. I have not used them, but I have toured the facility.
Blurb – If you go to Blurb directly, you’ll have some options that you don’t find in Lightroom, including different sizes and book styles.
Lulu is another company that has been around a while, but I’ve never used them.