My family & I went to Australia for month vacation in Winter 2000/01. We stayed at my dearest friend, we know each other since our teenage time(student time). (She married to a Australian and live in Australia).
We have plenty of tour from Melborne, 12 Apostels at Great Oceans Road to New South Wales... We visited the Penguin Parade in Phillip Island. If you are on Victoria, Melborne then I would recommend you to visit Philip Island.
Enjoy your vacation and good journey to there... I know for the sure, you will love it...