The value of online classes—more specifically, MOOCs—has been proven. In a study done last year by Coursera on people who have taken its classes, 72% of survey respondents reported career benefits, with 43% reporting improved candidacy for a new job and 26% actually landing a new gig.

Coursera offers quite a lot of very interesting courses and provides certificates after completing them. They're good not only for learning new things, but also revising the material that has been previously learned at a College.