Lay the book on a flat surface and open it to the first page to be scanned.
Place the car sponge underneath the side of the book with fewer pages.
Lay the sheet of glass on top of the open book, so it pushes the pages flat. The piece of foam should be thick enough that it presses the side of the book with fewer pages against the glass.
Angle the book slightly by placing a cardboard wedge under the top edge, avoiding any glare or reflections on the glass platen from ambient light. If you're unable to avoid glare from the ambient light, set up the book scanner in a darker room, and only use the lamp to illuminate the pages.
Fix the camera to the tripod, and angle it downwards so the camera is as close to parallel with the sheet of glass as possible.
Position the lamp so it illuminates the pages evenly, but without causing glare or a reflection visible by the camera. Make sure the flash is turned off on the camera.
Take a photo of the open book, lift the piece of glass, turn the page, and then replace the piece of glass. Repeat this step until every page has been photographed.