Sorry for the lack of info. The clamps hold down a peice of wood on the top of the sled. Expose the end of the wood just enough to cut a little bit from top to bottom of the peice. the sled has a datto down the center of it, as you push it through the datto you are "jointing" with the table saw. It is a very effective way to joint on the table saw and very accurate.
When I made it, I had it overhang the saw blade when it was in the datto channel and ran it through the saw blade the first time, giving you a perfectly straight and accurate jig. Once one side is done you are done with the jig. Install the fence and cut to width. Very nice if you dont have a jointer!