There are about 45 different Aboriginal languages native to the Australian Aboriginal people.
Per capita, Australians spend more money on gambling than any other nation.
When greeting, give a right-handed handshake while making eye contact.
Language in Australia tends to be very “colorful” (i.e. inappropriate by other standards). Never include issues related to immigration or Aboriginal issues.
Australians do not appreciate having their accent pointed out to them.
The phrase “I’m stuffed” should not be used when dining; it translates to “I’m pregnant”.
When dining, guests are seated to the right of the host.
In a pub, each person is expected to pay for at least one round of drinks.
Gift-giving is not a large part of Australian culture, however you can offer something from your country if you wish.
In business settings, Australians are very straightforward therefore making relationships unnecessary. They are also open to ideas, creating mostly collaborative work environments.

https://www.cia.gov/library/publications/the-world-factbook/geos/as.html (Majority of information)
http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/2071.0main+features902012-2013 (Ethnicity data)
http://www.abs.gov.au/ausstats/abs@.nsf/Latestproducts/2071.0Main%20Features902012%E2%80%932013 (Religious data)
http://abs.gov.au/ausstats/abs@.nsf/Latestproducts/3218.0Main%20Features12014-15?opendocument&tabname=Summary&prodno=3218.0&issue=2014-15&num=&view= (City population)
Wolfram|Alpha (Currency exchange data)
Information accurate to best of ability as of 25 October 2016