[firebrand39]

How about math? Being a programmer helped my get up to speed on math. And there are so many wonderful resources out there. My advice, do not buy a textbook and try to kind of linearly take in math from a single author. Pick a topic and then move around with Google following your interest and questions. Fill in the gaps with Google searches as you move along. This has been tremendously useful to me, and, yes, I am very grateful to Google. When I started, my interest had been piqued by machine learning. I did not expect to get as far as I did, hitting a wall sooner or later, but not so. There are really really great authors and blogs out there, explaining in plain language what you may not understand. You just have to find them and they are by no means all Ivy League. Although my current favorite is Steven G. Johnson from MIT.

[throwaway93834]

That's a good point. I have been working on my math skills independently, but haven't taken anything over Calc II in my time at university.