You'll make good money that will allow you to travel or save. Salaries and conditions vary according to the country and school, but they will pay for transport to the school and health insurance. You might also get free or subsidized accomodations and tax exempt salaries.
In addition to being a licensed teacher with two years experience you will have to provide three references (you have to get the reference forms for them. IST will not run after them) and travel without dependents and enjoy living and learning about new cultures and countries. You'll need to show copies of your qualifications and it can take up to a month for them to place you on the teachers' register. There's a one-off fee of less than $100, but it's well worth it if you're looking for a job at a quality school that's already been vetted by IST.
Got an idea for a job site?
Email me with your job site, name, and website (if you have one) and I'll post it ASAP.