HSBC have an excellent international service, and can help with opening local bank accounts and credit cards. Best to get all this sorted before you arrive.

If you need to stay temporarily in a serviced apartment before finding something more permanent I would recommend:

www.apartmentservice.com.au/

and

www.rent-a-home.com.au

and in particular:

www.mortonandmorton.com.au/

But the biggest tip I can give you is to learn about and apply for LAFHA:

http://www.britzinoz.com/info/lafha.htm