[applecrazy]

If he's really dedicated to learning about CS, I would recommend the curriculum at https://teachyourselfcs.com/. It outlines a traditional CS curriculum and the best online books/courses related to each topic.

As a high school student interested in CS, guidance like this has really helped me out, since I don't really have a mentor.

[ccantana]

Bradfield is an excellent resource and Oz and his team are fantastic.

The only caveat would be that a lot of Bradfield’s curriculum assumes that students have some programming background already, so it might make sense as a secondary resource after starting with some more basic programming courses.