For a current listing of courses, look at the interactive list, which shows courses offered by Sociology and other departments. To see Sociology, you'll need to select College of Arts and Sciences after Select a school, and Sociology after Select a department. To see all courses (rather than just the ones that are still open), select All courses after Select course status.
Once you've gotten the course list, levels are indicated as follows:
core = Core (SC001-SC099 for Sociology courses. Click here for more information on cores.)
one = Undergraduate Elective
two = Undergraduate for Majors
three = Undergraduate/Graduate
grad = Graduate Course