If I had more time I would love to go through the bioinformatics specialization on Coursera. They have 2 books and an exercise site (rosalind.info). It looks like great fun.
Design of Computer Programs was decidedly the best course I ever took online. I was lucky enough to take it when it was first offered. Peter Norvig was very active in the course forum.
Along the same lines but a more thorough treatment of linear regression and statistical inference is the excellent Data Analysis and Statistical Inference https://www.coursera.org/course/statistics