Will,

The main sheet runs from the block that mounts on top of the main traveler car through the jamb cleat then through the traveler car and finally through the small S/S loop at the rear crossbar. There you tie a figure 8 knot. Letting out some line through the jamb cleat allows the traveler to move out. I am sure the picture of this will show up in the on-line manual. The main sheet then ends up doing two things, letting the boom/sail out and controlling the traveler.

Howard