Ask HN: where to send a friend’s son for Programming 101?

I was with an old high-school friend this weekend and his son’s interest was piqued by the notion of learning programming, after I showed him a bit of code. The kid is 14 yo and suitably geeky, but has never coded.

I am happy to help teach (remotely) but I think that a) there are good resources out there and b) programming is largely solitary and c) I know more about programming than I do about education.

What is your most-recommended resource for learning programming, tabula rasa?