Best thing to do in Sydney (for free): You can walk from Kings' Cross all the way to the Opera house and Harbor Bridge in a few short hours.
Best Redeeming thing to do with no big town surrounding: Taggerty Bush Settlement, located about 2 hours outside of Melbourne. Run for the past twenty years by Bronwyn Rainer, this place is a refuge for orphaned aussie animals. You can help out by feeding or just holding them. amazing.
Best aussie moment: outback nights-clearest sky in the world.
Quick Tips:
Forget about the guide book and take advice from fellow backpackers and travellers.
Best Way To Get Around:
Australian public transport is probably among the best in the world, one word of warning: distance. If you plan to take a bus from sydney to perth, then be prepared for a 40 hour ride.