If you're interested in this type of stuff I can personally recommend MIT's 6.828 course (Operating Systems Engineering) as an additional resource. Specifically, you'll want to take a look at xv6, a teaching OS implemented for the course (http://pdos.csail.mit.edu/6.828/2014/xv6.html). The OS is small enough to print as cross referenced code listing (http://pdos.csail.mit.edu/6.828/2014/xv6/xv6-rev8.pdf) and has a book that fully explains each piece (http://pdos.csail.mit.edu/6.828/2014/xv6/book-rev8.pdf). You are only 9,000 lines of code away from fully understanding basic operating systems concepts!
Sorry just saw this comment. Work your way through the 6.828 course because the presentation of concepts in that course is as fundamental and bite-size as it gets. Then when you get to real operating systems (which are much uglier than xv6), don't be intimidated by the complexity. For any difficult subject, there's always a point along the learning curve where things seem hopeless but if you push through you'll start to gain glimpses of understanding. These glimpses provide motivation which in turn lets you understand more... eventually process of learning becomes self sustaining.
If it were altruism I'd applaud any effort. But their alailable lectures seem to be a bid to bring more students in to full enrollment. Poor video quality, as long as the awesomeness of the course itself can be seen, doesn't work against this goal.
It's been a few years since I took the class but it was an absolute blast. The offering in 2011 has recorded lecture videos (http://pdos.csail.mit.edu/6.828/2011/schedule.html).