Pros
Very flexible hours as you can choose what days you want to work, how many days a week you want to work, and you can choose half days or full days to work. You can sub for all grade levels from elementary, middle, and high school which is great so you can choose what you like to sub for. There are always jobs available for you to take so you don't have to worry about not working. The only benefit they have that you can apply for and get is insurance (there is a variety to choose from.) During all school breaks, there are no jobs to work so you get a break.
Cons
The hiring process is LONG (at least that was how it was in my experience,) it took almost 2 months before I could begin working. It's an easy process, but lots of requirements. It won't take you long to finish the requirements and get hired, but for some reason, Kelly takes forever to allow you to begin working which is frustrating. Also, they are difficult to get a hold of in the hiring process when you have questions whether it's over the phone or through email. You have to call and email multiple times before getting a response. Pay is also not great, but of course, teachers don't even get paid well themselves so I wasn't expecting to be paid better as a sub. They don't give bonuses or extra pay, but I also believe it depends on the county you're in because in some other counties, subs have better pay or get bonuses. As far as I know, there is no summer school to sub for so you are out of a job during the summer. During all school breaks, there are no jobs to work and you're not getting paid.