We've shown you a couple of methods for creating a hollowed out
book stash before, but it's not too often that somebody takes
the time to document their own effort on video. It turns out
there's a reason for that; it takes about 15 hours of hard,
paper-cut-laden labor to build one out of a larger book, which
is what you'd need to store anything more substantial than a
couple of CDs.  The Ultimate Instructional Video for Turning a
Book into a Secret Stash  Making a Book Safe | YouTube via
Instructables