You are supposed to apply for a Hong Kong visa to stay for more than 30 days. There are different requirements for different types of visa. For a tourist visa, you are supposed to submit the following documents:
1. recent photograph affixed on the application form
2. photocopy of proof of your financial standing (bank statements)
3. Photocopy of proof of your transportation arrangement (flight itinerary etc.)
4. Photocopy of proof of relationships with the local sponsor ( for family visit only)