Hi Gareth,
I have a lot of experience in proof-reading books, and believe me, you cannot properly proof-read a book in an hour

. The only way to proof-read is to compare the original book and the electronic text, side by side, and look at every word, every punctuation mark, etc. I am currently undertaking the mammoth task of proof-reading all the Charles Dickens books that I've created and uploaded here at MobileRead. I'm currently nearing the end of "David Copperfield", a book which I started proof-reading two months ago, and have spend approximely 2 hours a day on, 7 days a week, since then. That's about 120 hours of work to proof-read one book, and it's still not finished.
Proper proof-reading is enormously "labour intensive", and there aren't any shortcuts.
PLEASE don't use text format for your scanned books; you'll lose all the formatting, which adds so much to the book. Some "rich" format such as HTML will be enormously better.