First, students think of a movie they've seen and come up with a single object that could represent that movie. They download a picture from the internet, place it in an Illustrator document, and trace it with the pen tool. They type the title of the movie and pick an appropriate font. Finally they draw a rectangle to cover the page and serve as the background. Send it to the back, and pick a color for everything, and turn in a PDF of it.
They're mostly practicing the pen and type tools a little more, as well as learning about arrangement in Illustrator by putting the background rectangle in the back. For a more advanced class, I might try doing the assignment later and using Photoshop masks and brushes to make it look aged. But junior high students don't have a knack for subtlety that the Photoshop aging would require.
Another thing to consider for the future is to add a gradient to the background. These kids love gradients, and in this case they'd be motivated to make them look good.