Udacity has a CS101 in Python that you can start at any time and can be mastered by a 9 yr old with parental guidance. Check it out. I am sure you will be happy with it and your son will have a good time.
Their interface is a lot better and their teachers are great, they've really created a new pedagogy around the new medium rather than adapt existing brick and mortar courses like Coursera and edX is doing. Mind you Coursera and MITx is a great way to get real college classes over the web, but Udacity is rebuilding the whole paradigm and is intensely analyzing data and tweaking to improve things.
Their interface is a lot better and their teachers are great, they've really created a new pedagogy around the new medium rather than adapt existing brick and mortar courses like Coursera and edX is doing. Mind you Coursera and MITx is a great way to get real college classes over the web, but Udacity is rebuilding the whole paradigm and is intensely analyzing data and tweaking to improve things.
http://www.udacity.com/overview/Course/cs101/CourseRev/apr20...