Here's some shadow puppets and a set I made. The end picture is a little hard to see as I did this in the daytime and the shadows were hard to spot. I don't recommend doing a show in the day. Dark is good!
Step 1: The Puppets
First make the shadow puppets for your puppet show. Choose a theme for your show(I did a sea themed puppet show.) and follow these steps. To make the puppets draw some figures on the black card. Make sure the outline is distinct and can be easy to see through the set. Cut these out and draw features on them with a white pencil. (These are just to make the puppets look cool!) You could use my pictures as outlines if you want. After you've cut out the puppets and drawn on the features, stick a wooden stick or a long thin strip of strong, black card. These will make it easier to do the show with.
Step 2: The Puppet Set
To make the puppet set cut out the top bit off the cereal box. Decide how big you want your set to be and adjust the size of the box by making it smaller. Then cut off the entire section of the back of the box leaving the two small sides. Do the same to the front of the box but leave about two inches from the either side and cut from here. Cut the middle section of the bottom part of the box so there is a hole in the bottom but still enough card to make the box stand up. Cover the box with black card or tissue paper (you can also paint it if you don't have any of these things.)
Step 3: The Puppet Set
Get a piece of grease proof paper or tracing paper (whichever colour you like best) and make it the same height and width of your cereal box. Stick or tape the two ends of the paper to the front side of the cereal box. Then cut out two shapes that look like curtains from black card. Stick these to the edges of the box as well (make sure it's over the grease proof paper!)
I also made some waves and stuck these behind the paper so they would show up as well through the light. You can make any settings you like so long as they don't obstruct the puppets from being seen through the shadows.
Step 4: The Puppet Show
Now all you have to do is go to a really dark room, shine a light with a torch through the back of the cereal box and make the puppets act out a scene behind the grease proof paper. (You might need the help of a few friends!)