If I had to make a general suggestion, Patrick Spielman books were the first that came to mind but, if you just look for the
scroll-sawing section of the library, you can browse what subjects are covered that appeal to you.
I made a couple of puzzle from wedding pictures simply by applying a spray glue to the back of the photo and glueing it to a
piece of wood the same size as the photo. I then laid a puzzle template on top of the photo and taped it all around the
block of wood with clear packaging tape.
As you cut the pieces of the puzzle, the packaging tape with the template will just peel off your wood.
I did not coat the photo with anything afterwards because the photo is already pretty durable. I think I used 1/2" wood but,
you could probably go as thin as 1/8" if you wanted to. You can also cut the individual pieces free-hand with-out the extra step
of using a template.
Good luck on your future projects and God Bless! Spirithorse