Harvard's CS50x (taken through edX) is absolutely amazing as an intro to computer science. Professor David Malan is really engaging.
I cannot recommend it highly enough.
And, if you don't care for the certificate at the end of the course, it's free
I cannot recommend it highly enough.
And, if you don't care for the certificate at the end of the course, it's free
Alternatively, or in addition, you could follow this course with NAND to Tetris, which had its second addition come out last year and will give any student a firm foundation in understanding lots of low-level details with project-based learning that only requires some basic programming skill.