Ask HN: Learning Systems [Computer Science]

Hi HN!

I've been meaning to apply to a university for a program that has a strong focus on systems (OS, Distributed Systems). For the same, I'm required to do a couple of decent sized (i.e. university level) projects in C.

I have 2 questions

1. Are there any online courses that you'd suggest that has a lectures, assignments and preferably projects? Courses can be either like MOOC or just a course page with all the info freely downloadable.

2. Also, what are some good ideas on system level projects one can try working on (someone with no experience in C / OS) that uses concepts like threads, concurrency etc.