- Compilers: I'm taking the Stanford course on Coursera right now. It just started two weeks ago so you can still catch up. Here's the link: https://class.coursera.org/compilers-004 Here's some literature on compilers/interpreters/JIT (Just In Time compilation): http://www.stephendiehl.com/llvm/ (I've heard good things about LLVM!) http://blog.reverberate.org/2012/12/hello-jit-world-joy-of-s... (Just saw this today) Tutorial on building a Lisp in C, from two days ago: http://www.buildyourownlisp.com/
- Operating Systems: Definitely check out MIT's open courseware on xv6! It's an implementation of Unix version 6. The course includes a git project that you can clone and play with yourself, as well as some labs. Here's the link: http://pdos.csail.mit.edu/6.828/2012/index.html OSDev wiki had some resources too: wiki.osdev.org If you have a Raspberry Pi or are patient enough to try to emulate the hardware, here are some tutorials on ARM assembly for RasPi: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/
- Networking: Here, you'll probably want to look for tutorials on socket programming and the TCP/UDP protocol. People recommend Beej's tutorials, which are quite comprehensive and a good source of information, but I found some of his server code confusing and convoluted (deeply nested loops and if statements). Here's a link to his site: http://beej.us/guide/bgnet/ Here's a easy to learn server/client tutorial: http://www.thegeekstuff.com/2011/12/c-socket-programming/
- Graphics: I have the least amount of exposure to this, but a good resource is at the website open.gl. Basically you'll want to learn about shader languages and how the graphics pipeline works.
Hope this helps!