Depends on intended subject and starting skill level. Can ya narrow it down? I have a pretty good size library with them. Might be able to give a pointer.

Ooooo whatcha thinking? Coding language?

I picked up a couple of python, Java script and AWS courses

https://www.udemy.com/course/permaculture-design-course/

Not the best PDC itself though there are really tight informative parts deeper in. Just the stories from Bill, never sure how to take the man.