What are the options to stay in China for several years (spouse will be studying there for 6 years)?

Hi i'm flying for China to study MBBS for 6 long years in this Sept'13. How can i take my wife and son with me there for the same period? Is there any mandetory exit rule from Chinese Govt? That means- will they need to leave China every after certain months? We are Australian. My wife doesn't need to work or study there. But my son will need to go to school from Jan'15. It will be great if my wife has the permit for study and work. But it's not so urget for us. And as a full-time international student i won't have work permit in China. Could you please help me out with this information? Thanks.