Make a foldable book stand. Only some tape and cardboard boxes are needed.
My project is inspired by this instuctable http://www.instructables.com/id/Bargain-Price-Book-Scanner-From-A-Cardboard-Box/ which describes the general process of scanning well. And it has instructions for the editing on Windows.
In summary: to scan books using camera, you need:
3. desk lamp
4. sheet of glass (size of page or bigger)
5. some suitable book stand
6. time and patience to edit images and combine them to PDF
This instructable is about nr 5. The stand makes the process easier and results better than they would be when done simply on tabletop.
The most time consuming part at first is the editing, but it will shrink with practice. BUT note that setting up the software for editing is not the easiest one click process - be prepared to mess around for a while.