Balmain,
A good place to start would be the private schools in Hong Kong.
You can get a complete list on
http://www.classmateasia.com
The next place to start looking is the ESF (English Schools Foundation) which is a quasi govt organisation.
http://www.esf.edu.hk
Many of the schools will have contacts for those seeking employment.
A word of caution... living and making a living in HK is fairly stressful when compared to being a tourist. Having said that the asian / chinese ethos of respecting teachers makes life a lot easier for those in the profession here in HK.