Choose a simple subject for your animated picture, such as a melting snowman, for example. You'll need to make lots of drawings, so if you pick something very complicated, it is going to take a long time and may not turn out looking great. Line drawings work best for flip books when first starting out.
Draw the first stage in your action on the second page of your notebook. For example, draw an intact snowman. Do not make the drawing particularly intricate because you'll only see it for a second. Use pencil in case you mess something up; that way you can erase and fix it.
Flip to the second to last page of your notebook. Draw a picture of how you want your action to end. For example, on the second to last page you would draw your melted puddle with a hat and other snowman accoutrements.
Fill the pages in between the first and the last drawing with the action in your animation. Start with the first drawing. Every drawing following the first needs to change slightly so that it becomes more similar to the last drawing. For example, the drawing following the one on the first page would be very similar to the first, intact snowman, only this snowman may have a slight frown instead of a smile or he might be slightly less round due to his melting. Place your drawing in the exact same spot on the page as the previous drawing. The closer to the previous drawing you get, the better your animation will look. Continue making these slightly altered drawings on each page until you reach your end point, in this case a melted snowman.
Close your notebook. Flip the pages in your notebook with your thumb as fast as you can while still seeing the images you drew. You should see an animated picture as you flip through your pages.
Go back through your book and add color and detail if you're pleased with the way it turned out.