Any ideas on how to decorate ugly garage windows?

I have a second, unattached, garage next to our house. It has 4 long, evenly spaced windows. Some are cracked and you can see in to it. The outside has not been sided yet and has plain weathered looking wood on it. I was thinking of putting a boulder under each window or a bench under the windows. any other ideas? How can I cover the windows so you don't see into the mess? I'm a single mom and don't know how to do anything too involved. Also, I rent. Thanks!