They are called helicopter pilots. And I don't know of anyone sky diving from a helicopter. I have known a couple of helicopter pilots, and they even sky dived from a plane. (I grew up near a world class skydive facility.) As for the pilots that drop snowboarders and skiers in the mountains, I am not aware of any special licensing for that, but you would definitely need a acquired skill set.
To be a helicopter driver for snowboarders or sky divers to set them in a location, do you have to be hired for that, as a specific driver or you could be a regular helicopter driver?
You have to be HIGHLY skilled since they are dropping those guys in seriously windy and rough conditions . . . So if your not young and already in taking Lessons, then forget it . . .
You have to have so many hours of flight time to make it to different tier jobs in Helicopter flight.