Tunnel Books are simple to make and they look awesome too! They're generally comprised of pictures (but they don't have to be, be creative!) and they're constructed in a such a way that when you look THROUGH it it gives the effect of looking at sort of a 3-D landscape! They can have just a few "pages" or a whole bunch... they can tell a story or just show a landscape or whatever. Go wild.
Step 1: create your images
Things that you'll need are:
colouring tools of your choice
hot glue or Epoxy
The first thing you want to do is start sketching and plan out your story or whatever it is that you want to put in the book. The thing you have to keep in mind is that most of your illustration is going to have to be on the sides of the pages... it's going to have to be on the borders so you can still look through the tunnel... but hey it doesn't have to.... but you want to keep in mind that if you have too many things in the middle of your vision you're not going to be able to tell what's happening. Another thing you want to keep in mind is that the borders of your "pages" will slowly continue to get wider as they move back in the book to get that tunnel effect, so keep that in mind as you're sketching our your ideas
Once you come up with your idea, put it on any kind of paper that you like colour it out but leave a space in the middle. See how I made mine below? Then lay them and glue them flat on some matte board so they will be more study in the final project.