can I go to china and stay there for 3 or more yrs and work as well and how do I go about doing so?

You should apply for a Chinese work Z type from your home country to work and stay in mainland China legally. You should first prepare those documents including your passport and copy of its data page, a completed application form, a recently-taken passport-style photo, alien employment permit and others, and then go to the China embassy to make the application.