Free online courses from top universities
The breadth of open resources has never been greater than it is today, but unfortunately, it's useless without some semblance of structure.  If you have very specific gaps you're trying to fill, it's easier to pick out from the lot, but what I think will be more helpful is aggregators making clear tracks, as many MOOCs have now done (in many cases as paid offerings, although you usually can audit for free). I'd rather my choice be around what I want to be able to do or what broad specialty I'd like to pursue and someone else with the knowledge tells me what specific courses to take--much like we do at university!