Working for the Physics and Astronomoy department was great. I was also a student in the major and learned a lot about the registration process, degree coursework, and general physics knowledge that I wouldn't have been exposed to otherwise.
The workload is very minimal and casual. Helping organize paperwork, handling incoming mail, and working on office project makes up most of the day-to-day responsibilities. You'll often have time to work on your assignments for class.
Great supervisor and department staff.