The wheel should have the secret message or picture that peeks out when you turn it.
Once the pictures are drawn put the picture that will eventually be hidden on top of the picture that will eventually be your front cover. Punch a hole in the center of both and put a handy little spinner-fastner. Then hide the flaps of the top one underneath the front cover.
Variation: Cut two identical copies of the wheel and turn one backwards to insert into the other. This variation makes it easier to turn but somewhat less stable.
Draw three circles. The largest is going to be your base. The medium one is going to hold the secret picture. It should be able a half inch smaller than the base in diameter. The smallest size circle needs to be about an inch smaller in diameter than the base and you need two copies of it. You also need to trace it onto the two larger circles.
Take your two smallest size circles and draw a very small circle in the middle of them (about a half inch in diameter). Then divide them into quarters so that you have a total of eight small pizza pieces each with a bite out of the tip.
Draw lines dividing your large and medium sized circles into eighths. Take the pizza pieces and tape them to the lines on the largest circle (the base) so that they lay overlapping each other.
Draw a circle in the middle of your medium sized piece of paper just a little bit smaller than the very small circle you drew on what became the pizza pieces. Your medium circle should now have a tiny circle near the middle and a circle near the outer edge. Imagine this as a model of a planet with a center core, mantel and crust. It should also have lines drawn across dividing it into eighths. Cut along the lines in the mantel part leaving the core and crust whole. Then flip the sheet over (so the lines you drew are not visible) and draw a picture or write a secret message.
Then carefully insert the flaps from the base into the slots so that they can fall over and completely cover the picture you drew. You may need to enlarge the slots slightly if it doesn’t turn easily. You should be able to turn the middle circle to reveal the picture or hide it. Draw a picture on the flaps to be a “front cover.”
If when turning the circle to reveal the secret picture the flaps come out of the slots to easily, you have two choices. One is to put a bit of tape folded to prevent the flaps from moving back that far, but then there will always be a bit of the secret picture covered. The other alternative is to carefully tape pieces of cardpaper to the back of the circle with the slots, so the flaps rest on the extensions and will go back through the secret picture easier.