Before you fly — Weeks before departure
Tourism Australia
The national tourism board, with itineraries and regional guides.
Tourism Australia
australia.com
Worth doing Official Free
The national tourism board, with itineraries and regional guides.
Genuinely useful for working out what is realistic in the time you have. Each state also runs its own board with better regional detail.
SourceTourism Australia
This is one entry from G'day Guide — every official service, help line and useful site for arriving in Australia, explained in plain English and put in the order you actually need them. No affiliate links, no sponsored placements, no paid rankings.