Pros: a good job for a parent with a college education who has school age kids, since it is during the hours the kids are in school, flexible in days you want to work.
Cons: as a substitute there is no training, since they assume you have a teaching degree or are in the process of getting one, to maximize being called for a job, one has to sing up to work multiple school sites, this results in different schools, time start is different, lunch breaks, prep, discipline at each school is different, everything is constant changing everyday.
Kids are fun and challenging. Different rules for different schools is hard to keep up with. Constant change throughout the day. No training.