CaspersCruiser,
In addition to Jim's excellent instructions, I would add a couple of more comments:
1. When you winch the boat forward while the trailer is in the water, the bow should end up touching, or almost touching, the bow roller on the trailer. However, when you pull the trailer out of the water, you will likely find that the bow no longer touches the bow roller, possibly being 2-3 inches away from the bow roller. Then when on level ground, you will likely need to "bump" the boat forward to again touch the bow roller, by proceeding at a very slow speed then tapping the truck's brake hard. The boat should slide forward that last 2-3 inches. It is a trial and error approach to how to accomplish this.
2. I strongly suggest some type of adjustable tie-downs (2 of them) be attached to the stern of the boat then to the trailer. Some people have an adjustable strap that goes over the cockpit, with chafe protection where the strap touches the gunwales of the cockpit, then to each side of the trailer frame.
3. I also suggest another adjustable tie-down be attached to bow ring of the boat then to the trailer frame.