I have been to Australia twice now, It's a beautiful country. There's so much to see and do, so much wildlife and VERY welcoming people!
The only thing is ... some of them are very far from the sea, and quite dry. Makes those beautiful beaches even more attractive, when you have been far from them for a while!
Go to the Blue Mountains to see the worlds steepest train and the aboriginal man who sits there year in and year out playing his didgeridoo.
Make sure your Aussie friends take you out kangaroo chasing - this can be rather fun! Just watch that you don't have one of them hit into the side of your jeep ... Whoops!
Watch out for snakes and tarantulas in summer.