Also, before you send them off, go into Preferences and look for the one pertaining to iPhoto.
Inside that .plist file are 3-6 settings pertaining to the print quality of your PhotoBook. After your book is made, it's sent off as a PDF to Apple. To keep the file size down, the quality isn't as great as it can be. You can change the settings so that it prints at 300 DPI instead of 180 DPI or whatever they use. There's a massive massive difference going to 300 DPI, but the file size is larger, so uploading takes ages. You can set it higher if you want, but it won't come out much better after it's printed.
They look excellent. Great photos. Much better than hand-pasting the photos, and only costs around 2x more than having digital photos printed at a shop. But then you'd have to buy the photo album anyway.
If you want me to help you find the settings related to PhotoBook quality, let me know.