Pros
I had a few different student jobs at WVU Libraries and they paid for my tuition, which was cool. I loved everything about my reference assistant position. Fulfilling someone's research request, being able to give them the missing piece of their historical puzzle, is the greatest feeling in the world.
Cons
My other job was as an archival materials processor and it was miserable. It required sitting alone under fluorescent lighting doing monotonous data entry all day. The social isolation and monotony was very damaging to student workers' mental health and we received no support in that regard. When I made a friend, they moved him to a different desk. This job did teach me some professional skills, but unfortunately I will never be able to use them because the experience scared me away from cataloging for life.