In graduate school, I TA'd a course on data structures in C++. I absolutely loved it. As an undergrad, I loved the course, and having the opportunity to really master the material well enough to teach it was a great learning experience. I was a pretty darn good TA too, rated among the best in the department every semester via reviews by the students. Unfortunately, there was a limit on how many semesters you could TA at UIUC, and they kicked me out after my 3rd. Anyways, I put the my discussion notes online because friends of students would ask for them periodically. They lose a lot without whiteboard examples and discussion, but I've been told they are still helpful.