I need some pointers from others that have organized races at their launch.

What is needed?
What does the course look like?
Do you have sponsors local businesses donating prizes?
What time works best weekends, weekdays after work, mornings, afternoons, or evenings?

Take a look at the notice of race for the worlds in SF starting tomorrow for a good coarse diagram. Most appear to be using a standard triangle. Start gate going upwind with a windward mark, optional offset mark, off to the left of the course if you are looking from the start a triangle mark at 45deg then down to a leeward turning mark for around twice or back to the start gate to finish. Optional upwind gate for finish. If you have no idea WTF I am talking about go to your local yacht club and volunteer for race comity duty. I would also try not to schedule on the same night as the local weekly bear can races. Most places do the weekly race on a Wed night and then offshore and big regata's on the weekends.

you need about 3 buoys and a boat. Then a race director and about 3 people to help out, who control if the riders make the buoys and who finishes.

You also need: 1 red flag, 1 yellow flag and one green flag. Also a horn.

Find the racing rules on the PKRA site and read it, to know what to take care about. Also make sure the racer get to read the rules.