There are a lot of big names out there, but I like Martin Chuck's lessons. (You can search for his YouTube channel.) My son learned from a local pro, but the teachings of the pro is very similar to what Chuck teaches online.
As I mentioned in another thread last year, the baseball swing and golf swing have a lot of similarities. Half of our school's golf team are baseball players. The baseball swing taught them good weight transfer, keeping the head still, and a powerful swing. Many baseball players are long hitters in golf. My son swings baseball bat ~80mph; with a golf driver, he does an easy 3/4 swing and boom, 280 yards down the fairway. Another baseball power hitter hits his drives ~300 yards consistently. For them, the short game is the key, since there's nothing like chipping and putting in baseball. If they can figure out the shots around the green, they can be competitive golfers.