Pros
You can work or not work as you choose
Cons
Pay goes down every year. $85-$100 per day, or less. No holiday or sick day pay. No pension. Your job could be cancelled without notice. Will not lead to a direct-hire teaching job at the school - those jobs go to family and friends of the teachers and board of education members. Can be fired at any time for any reason. No union to back you up. Students can go home and say the most crazy stuff about you and will be believed before you will. Poor health insurance coverage. Sources4Teachers/ESS was formed just to break up the teachers' unions. Instead what happened is most schools to save money (to pay for ever increasing teacher salaries) have outsourced their substitute teachers, paraprofessionals (who work harder than most teachers in my view with no prep time), custodians and bus drivers.