There is one big fundamental for getting to Australia (other than a flight) and that is an Australian visa. This is permission by the Australian department of Immigration and Citizenship for you to visit or stay in Australia.
If you are going as a tourist it is easy. If you have a return flight then you can an elctronic tourist visa.
If you want to live in Australia it gets more difficult but then I guess it has to.
There are a large number of visas available and knowing which one is correct for you involves hours of researching for the right ones (and a bit of guess work) or you can pay a migration agent for an a detailed assessment. The assessment will point you in the right direction and after that you can decide wether you want to apply for the visa yourself or use the services of a migration agent to complete the application for you.
Some visas are simple enough (working holiday, business trip) and other are incredibly complicated and time consuming (skilled migration, employer sponsorship, business skills). The longer you are applying to stay in Australia for the more difficult the visa application is as a rule of thumb.
The whole procedure is governed by law in Australia and there are fromal procedures for authenticating documents and applying to specific locations.
A good starting point is the government website for the Department of Immigration and Citizenship http://www.immi.gov.au/
However, If you want to appoint a migration agent who is MARA registered and can provide you witha detailed appraisal plus full preparation service we recommend DNA Migration. http://www.dnamigration.com
