This project was floating around Pinterest some time ago and I can't seem to find where I pinned it but it is a really fun project. All you need are some old books (got mine from the thrift store of course) and to cut out the pages.
The easiest way to do this is to run your exacto knife down the pages on each side, at the beginning of the book and the end, as close to the spine as you can get, and it will make the pages fall out in one nice chunk. After that, use the ruler to help you keep a straight edge and cut out whatever part of the cover that you would want a picture to go and in what ever size. Do whatever feels right to you! Go with the flow! Just be yourself! The sky is the limit! (I hope that helps your decision).
Shown above, I used the book pages that were cut out to create a little display of a brooch (also from thrift store). Just glue the pages together to make sure they stay together when you hang them up!