Distances are great and temperatures often unpleasantly high. Thus two of the most important requirements are plenty of water and covering from the rays of the merciless sun.
Stamina is another vital quality. The bicycle is an option worth considering for the east coast, where communities are not too far apart. There are some problems, though. Roads are often comparatively narrow and traffic is travelling at speed, making cycling unpleasant.
Nevertheless, cycling up or down the east coast, and across to Adelaide
, is certainly perfectly feasible and there have been books published recently recommending to the cyclist less frequented but reasonably surfaced routes.
Especially be careful of vehicles crossing each other and having no spare road for the cyclist. Cyclists usually prefer, understandably, to get off main roads, but in Australia that is not always easy. The minor roads are even more narrow, although with much less traffic, of course, and they tend to degenerate into dirt surfaces unpleasant for those on two thin wheels.
Going further west, though, is more difficult, although not impossible. You really need to be well prepared for this - and the most important supply will be water. Be prepared to cover a stretch of 200 kilometres without replenishing supplies and then you can probably see Australia by bicycle.
In cities cycle tracks are often found and an ideal way to travel around.