Australian Dollars; A$. Banks tend to offer the best exchange rate but only the larger branches offer the service. ATMs are a great way of getting a good rate and cash at short notice, just watch out for hidden bank charges.
There is no official language of Australia, but English is spoken throughout.
Use +61 for Australia followed by 2 for Sydney numbers (the same code also goes for Canberra too).
Visitors from the UK need a valid passport and an electronic visa to visit Sydney. The visa can be filled out online for no fee or obtained from your travel agent or airline for a fee of A$20.
Australia visa website