The laws are different in every country. I am not familiar with those in Australia. I would certainly start by checking the legal requirements which are likely to be found on a web site that either is operated by one of the large cities in Australia or a web site hosted by a financial or business authority for the country. ( like the IRS - Internal Revenue Service, would be here in the US)

Aside from the legal requirements, the idea of an import/export business is similar worldwide. Just note that, again, each country has things that it will and will not allow to be either imported or exported. So be certain you are staying clear of those items or products.

You would identify those items you plan to either import or export. You would set up relationships with suppliers and with shippers. You would decide how and where goods will be housed either before shipment out or after shipment in.

You would take all of these factors into account and put together a preliminary budget to make sure the business model makes sense and is doable. It is important to take into consideration ALL the factors of cost- both direct and indirect - to be certain you still have room for a profit margin that makes sense.

I would also check to see who in your area works on issues of importing and exporting. Is there a trade group? Is there an organization in one of the larger cities that deals with these issues? I would make contact with them and see what literature and recommendations they might have. I would also check with some who actually run import/export businesses and take advantage of their knowledge and expertise.