For scanning paper books, I use the CZUR Aura, which I love.

Some things I love about it:

• Takes a photo of two facing pages at once.
• Automatically adjusts the image to remove page curvature.
• The associated software does better OCR than anything else I’ve seen. Starting from a printed book, it averages maybe 1-2 OCR errors per page.
• Has a foot pedal so you can click with your foot while holding the edges of pages down with your hands.
• Automatically edits out the bright yellow page-edge-holding-down pieces of plastic.
• Folds up to be relatively portable.

There are a few minor quirks in the UI, and I don’t have a need for several of its features (like the ability to operate as a desk lamp). But I’ve used it for all of my book scanning for the past few years, and I highly recommend it.

One potential minor downside: when you export to MS Word, the software aims to reproduce the look of the original page, so there are some weirdnesses around things like font size and page numbers. If all you care about is the text (rather than the layout), you may need to do some additional steps (like select-all and then copy and paste into a plain-text editor or a new Word document) to remove the formatting.

(Caveat: I haven’t used any other book scanners, so I can’t compare it to how well they work.)