I would recommend starting with a real effort to build a team of dedicated teachers by offering them proper working and living conditions. The students will be able to sense a situation where the school has an adversarial relationship with teachers (as is the case with many language schools) and it will, in turn, harm the business. In addition to getting information here at ESL Teachers Board, here are some links you can start with to read up on what teachers are looking for in contractual relationships with a school:

http://www.chinaforeignteachersunion.com/2014/01/china-foreign-teachers-union-contract.html

http://eslwatch.info/forum/china/19-all-about-contracts-for-china-expat-foriegn-teachers-the-good-bad-and-the-ugly.html

These links are just a tip of the iceberg. You'll be able to learn a lot to help build you business with only a little research online.

-S. Knight