Pros
I worked with PR before I went to medical school and now I"m back after my first two years. It's a great part-time opportunity and you can do as little as you want or as much as you want. Before I left, I did like 3-4 classes at a time and now that I'm also studying I have only taken on 1-2 classes. There are so many things you can do like teach the classes, proctor tests, hold marketing events, be a private tutor. You get paid for everything - any extra help sessions you hold, emailing students, preparing for the classes at home, checking essays, etc (at a lesser amount). Communication with the office is awesome - all through email and they try their best to give you everything you need.
Cons
If you work far from the office, it might be hard because you have to go pick up the books and materials every time. You can get paid for mileage though so it's not so bad just time consuming if you have other jobs.