Altering books can be a fun way to create something beautiful and personally meaningful out of something that has seen it's better days. Creating something that expresses a rebirth of perhaps a lost idea is for me a deep personal communication of understanding a new value to aging.
There are many ways to alter a book; I'll show you what I have done. I first found an appropriate book, I personally picked The Land of Oz .for its title, it's illustrations, and it is also in the public domain. I always scan through the illustrations to plan where put things in the book that I think represent the story visually.