If you're willing to cut the books, use anything with a document feed. Doesn't have to be the fastest scanner in the world then as the process is automatic.
Otherwise get a camera and a lamp and build a rig. If you do it right it's fast as you can flip through pages without moving the book, whereas with a scanner you always have to pick the book up flip the page put book back in etc.
Otherwise get a book scanner such as the Plustek. It's still a tedious process scanning a book either way.
Alternatively, just download the book. If you end up having a digital copy of your book without paying either way, does it really matter where the digital copy came from?