Well, it depends on just how "reading condition" your copy was already, how much you care about condition (as separate from readability), and exactly how the book was bound. On the fox giants I've scanned, they were several rebound issues minus covers, so there were 4 or 5 separate signatures. The books were already in such a condition that I gently removed the cover where the glue was loose, undid the staples so I had 4-5 regular but coverless copies, scanned those, then reinserted the staples. This may be further than you wish to go, though!
Eric: You use your copy of Overstreet to press down the scanner lid? Me too! (For all its flaws- and I don't trust it as a price guide for a minute anymore- I still find it useful as a reference book in many ways. But I only buy a copy every few years when I like the cover art or my old one is falling apart.)