Using a Registered Migration Agent:

Australia has a very complex migration system and laws. Therefore applying for a visa should not be considered as merely a form filling exercise. Any advice you receive regarding Australian immigration must be from a registered migration agent. To check if any individual is a registered agent, whether their place of business is in Australia or overseas, please click on the link to the Migration Agents Registration Authority and follow the agent search instructions.

http://www.themara.com.au/Online/Default.asp?DeptID=121