As Above, plus there are a number of books. Chapman "Piloting and Seamanship". Earl Heinz's book Anchors, Nigel Calder Book on Boatowners Mechanical and electrical manual.
An old book, but good information: Royce's Powerboating.
Buy or download the Coast Guard rules of Navigation, I keep one on the boat.
There are also advanced courses by the Power Squadron. One of the advantages of both CG Aux, and Power Squadron, is that often you can go out on some other boats as you make friendships.
Most likely there will be C Brats in your area who may need crew for a day, and you get some experience there.
After you buy a boat, it would be advisable to engage a professional skipper for a day to show you the fine points of boat handling.