I just posted this link in another thread where the OP asked for ideas/suggestions for learning on a computer with some work downtime.
https://www.coursera.org/It's an organization that offers *free* online courses from various universities and colleges (complete with readings, video lectures, online tests and homework) on a ton of different subjects (I'm currently taking an intro stats course based out of the University of Toronto, and I'm registered for another stats course from Princeton that starts in the fall). Some of them even send out a 'certificate of completion'. I thought this might be a) a good challenge (learn something new!) and b) might be good for those who want to investigate a new skill (i.e. stats, finance, programming, global health policy) but want a more structured (but still free) environment to do so.
My problem was trying to resist registering for a ton of different courses, since I still have that darn dissertation/PhD to finish ;) While I don't need stats now, for some of the policy work I'd like to eventually do - this is a good place to start. For free! (Did I mention it was free?).