maps or GPS
Hema maps cover the country, with maps scaled to provide enough detail for your average bike tourer. They are common enough in newsagencies, camping stores and roadhouses, but sometimes the local map can be sold out, needing some fossicking to locate.
There are Hema regional maps: Kimberley, Flinders Ranges, Top End, etc. These are often annotated with brief descriptions and histories of some local features.
The Hema Great Desert Tracks series of Central Australia covers the more remote country at a scale of 1: 1,250,000. These are great to show the usual things: the class of the road/track, the size and location of settlements and the station homesteads. They also show information not shown on other maps: community store or roadhouse opening hours; extent of sand dunes and their direction; often water tanks, waterholes, boreholes, etc. If you are heading up the Tanami or traversing the Great Central Road, it’s all very useful information.
There are a couple of specialised map sets for the long-distance bike trails: the 900 km Mawson Trail from Adelaide to Blinman in the northern Flinders Ranges in South Australia, and the 1000 km Munda Biddi Trail from Mandaring just east of Perth to Albany in Western Australia. Google is your friend to track them down.
GPS with a decent 4WD map set is fantastically useful if you need that much detail. The downside of mobile phones or most GPS units is the pathetic battery life, which can be frustrating when it’s a week or two between power outlets. You will need to travel with a solar recharger or a bunch of power banks.
But you already knew that.
If you stay for a while in the capital cities, there’s usually a map of the local bike paths, which can make it easier to get around.