In addition to NPH's post, do a yellow pages search on "flying schools" rather than "aero clubs".
CASA will issue a Certificate of Validation based on your overseas licence which is valid for 3 months or when your overseas medical runs out, whichever comes first. Then you have to do an Aeroplane Flight Review with an apporoved instructor, doesn't have to be a CFI, but can be any Grade One or a Grade Two with CFI approval to conduct reviews. This flight will failiarise you with local procedures, some of which are a bit wierd, and will usally involve airspace entry and exit procedures as well as what you would expect on a skills test in terms of flying technique and aircraft handling in a rather different environment than you may be used to particularly in terms of temperature (density altitudes, leaning mixtures etc). If all is well then you get the stamp in your logbook and off you go. Ask the school about good places to go and visit. Although the coast is easy, it is much more scenic than some of the inland areas, beautiful though they are. Don't be afraid to ask for an instructor's help with your flight planning, and most of all have a great time!