For this project you will need some 6 mil plastic. You can find this in the hardware store, usually in the paint section near the drop cloth's and tarps.
You will also need a grommet kit. I used 3/8" grommets, but the size will depend on the diameter of your tent stakes. Get the smallest size that your tent stakes will fit into.
Finally you will need a pair of scissors that are sharp enough to cut the plastic. Regular household scissors should work just fine.
Step 1: Watch the Video!
The video explains all of the steps. It's really very simple, but effective.