Start by using an android cellphone or tablet with a good rear camera. Install Tina Time Lapse (free).
Put the camera on something about 1-1.5 feet off the ground, like a chair seat or center table, with the rear camera set off the edge, facing the floor. Or you can put a 16" box on top of a table and do it that way.
Sit on the floor and put your book on the floor and open it so you see both facing pages on your camera.
Put on a rubber page-flipping finger pad. Set your phone to not turn off. Set Tina Time Lapse to take a photo every 4 seconds.
Hit start, and just flip a page and flatten it down, watching the android screen to make sure it's lined up, every 4 seconds.
A 450-page book takes 15 minutes. Listen to a song or two. A shorter book will be done in 5. Now, all you do is let your computer convert it into an ebook.
Connect your camera to your PC, copy the photos if needed, and start up FineReader 12 (30-day free trial).
In FineReader, choose "File (PDF/Image)" and select the photos and adjust all the settings (language, b&w (faster) or color, "detect page orientation" and "split facing pages.").
Check back when it's done and you can then output it to PDF, Word, EPUB, etc. in FineReader or convert it to many other formats using Calibre (free). If the OCR (image-to-text) resulted in a lot of errors (bad camera), then using the PDF output is best. Then copy to your ebook device.