Use this site to find the specific requirements based on country of origin. Just choose your country of origin from the drop down menu and you'll be routed to a page with the pertinent information:
http://www.daff.gov.au/aqis/cat-dogs
For disability assistance dogs, use this page to find the correct instructions based on country of origin. Note: you must have at least 6 months of residency in the country of origin prior to import to Australia. If coming from a country with rabies, your dog must be microchipped, have a rabies vaccination less than 12 months old, and have a rabies titer at least six months old along with veterinary health certificates.