I know that some people will disagree with me violently, but you can self-learn pretty much any topic in CS as long as you are willing to put in the effort (any topic in any subject, really, the main factor is motivation). As someone who skipped straight to a masters, I know it is certainly doable to self educate.

MIT open courseware might be a good place to start, although I've never used it myself.

http://ocw.mit.edu/courses/electrical-engineering-and-comput...

I would personally focus on topics that are either historically difficult, or pragmatic.

So stuff like compilers, computability and complexity, operating systems, database systems, cryptography, machine learning, web applications, linear programming, networking. Learning the basics of hardware is important too, although it is more electrical engineering and math theory.