Pros
I have a wonderful team, and most of my coworkers are very intelligent and committed to their jobs and the mission of the library. Every day you get to meet new people, learn new things, and find more cool books! Most of the challenges are fun to figure out how to overcome. Also, you have access to great health insurance (though it's only affordable if you're full-time) and the ever-more-rare pension plan through the county.
Cons
There is no real communication from upper management or county management above, which was especially hurtful during the COVID-19 crisis. There is definitely an unnecessary sense of hierarchy too, so Library Assistant are often made to feel as if their skills and opinions do not count. They also pay the hardest workers (Pages) minimum wage, and meaningful raises are hard to come by and almost impossible to petition for. Very few full-time positions means that the competition for one when they open is insane, so be prepared to be stuck in a temp or part-time position for several years unless you brownnose a bit. Weekend and night shifts are required for all, but library assistants will be asked to come in for them the most.