Hiring a car, caravan or campervan is relatively easy. Major international rental companies operate here and there is no shortage of local companies, some offering very low rates.
Many national driving licences (including Canada, UK, USA) are accepted but, if they are not in the English language, a certified translation is required. For details visit http://www.australia.gov.au/content/driving-with-an-overseas-licence
If your licence is in a language other than English I recommend that you obtain an international driving licence before leaving home. You will need to show your national driving licence so don't forget to bring it with you.
Driving in the more settled parts of Australia is little different from other developed countries. The same can't be said for outback driving … see 2 The Outback, above.
If you come from a country that drives on the right, remain acutely aware that we drive on the left. One of my hostel guests died in a head-on collision when he strayed onto the wrong side of the road just north of Townsville. Another was killed when he looked the wrong way when stepping off the pavement (sidewalk). Be particularly careful when approaching roundabouts. Go round in a clockwise direction. It's appallingly easy to get it wrong.
Passengers and drivers must wear seatbelts and small children must be secured in safety seats appropriate to their size. It is an offence to leave small children unattended in a vehicle.
Most intersections are regulated by Stop and Yield signs. Where there are no signs, the driver on your right has right of way except at T-intersections. At these, the driver who is proceeding straight on has right of way.
When you leave the bitumen (tarmac) and drive on dirt roads, you won't see many road signs so bear these rules in mind. In country areas you may come across railway crossings without gates. Make sure you stop before crossing or you may add to an alarming list of casualties.
Finally, don't forget to lookout for wildlife. Kangaroos and other jumping creatures are most at risk (together with any vehicle that hits them). You are most likely to encounter wildlife at dusk and night time.
Many country people fit their vehicles with bull bars (also known as roo bars). I fitted them to mine after I hit a feral pig. The porker rolled over a few times and ran off. My radiator was wrecked and I had to be towed. The accident happened in town. It would have been very expensive if it had occurred in a remote area.