Pros
WorldTeach is a great program, especially if you have no previous teaching experience. It's one of the most legitimate companies when it comes to placing teachers in China and the support they provide is really above and beyond what you'll find anywhere else.
Cons
Most people only stay one year because your salary is about a third of what most foreign teachers get paid, and while the company does what they can to provide support for it's volunteers, I had several colleagues that felt abandoned by the organization and sank into depression during their time in service, some even choosing to leave before their contract was up. Don't expect to feel like a volunteer providing a service to people in need. The reality feels more like a full-time job, and you are placed at the top schools in the province because they are the only ones that can afford to sponsor you. Many volunteers found themselves feeling more like cheap labor rather than a respected member of their community. The schools pay Worldteach upwards of 76,000 RMB each year to have a foreign teacher. The year I served, we were paid 33,000 RMB of that total over the course of 11 months, the rest goes towards program fees. If you decide to go with this program, be aware that you are contracted to teach at least 16 classes per week. Most volunteers saw upwards of 1,000 students every week. Classroom management and communication with the school can be the hardest parts of employment. Having an elementary proficiency in Chinese before you arrive helps a TON! Do your research, and know what you are getting yourself into. While you may have experience teaching abroad, teaching in China is an experience unlike any other.