I sub now. I have young kids so the schedule works. Here is my experience:
-Some subs do it every single day they can, which is basically full time (except for the first week or 2 of the school year).
-Our district pays 90/day, the neighboring, poorer one pays 100.
-In Ohio, you need a 4 year degree and some online training, and a background check. If you have enough credits in subject areas, you can take long term sub jobs, like maternity leaves, which pay twice as much.
-In Ohio, you have to participate in the teachers retirement program. I can ~10% of my paycheck deducted for a 401k-like plan, and the district matches. I have to stay 5 years to keep that match, but I can roll over my contribution at any time. Since I am not actually retired yet, I like this.
-You can sub as an aide, school nurse, secretary, or bus aide for ~8$/hour.
-The nurse and secretary jobs are super easy, I read my book half the day. Well worth the lower pay.
-Aide jobs are hit or miss- they are fun for the little kids, but a MS or HS student with an aide typically means they have some pretty severe needs. They can be hard to manage.
-Subbing for a whole class is realllllllly hard, even in my high performing wealthy district with minimal behavior problems. I cannot even imagine subbing for whole classes in a low income district.
-I love the special ed jobs because you are working with 1 to 5 kids- this is manageable as a sub.
-I often teach HS classes in my area of knowledge (math/science). This is fun, as I get to actually "teach". Subbing higher level classes not in your area of knowledge is often mainly about keeping the noise level down and people on task while they do independent work that they know full well won't be graded for credit.
-You will discover certain classes are a total nightmare. You will learn over time to never sub for those teachers. But to learn that, you have to suffer through it first!
Overall, as an introvert, subbing is pretty challenging. I do it about 2 days a week and that is plenty! But I keep doing it because I love that I can work whenever I want. I don't take jobs if there is good weather, or I make plans, or I have a sick kid, etc.