First, build a box. We used scrap plywood and simply constructed the box using pocket hole joinery. You can also use glue and nails. The RYOBI cordless brad nailer is a great tool for this. Our box measures approximately 12 inches wide by 6 inches deep by 9 inches tall. You'll want to make your box according to which books you choose to use, as well as the height/depth/width of your bookshelf.
We tried different methods of cutting the book binding. The RYOBI reciprocating saw worked best. Clamp each book to your workbench and cut through it with the saw.
Use the RYOBI hot glue gun to attach the book bindings to the box.
Be sure all the spines are facing the right direction (not upside down!).
Finally, use the reciprocating saw to cut through only halfway through the two books on the ends, so that the sides of the box will be hidden.