I was there in 1997, and Adelaide is a great city. I second that idea of reading Bill Bryson's book. It's funny and will give you great ideas of things to see and do.
Have to greatly disagree!! I lived in Adelaide for 3 months and christ I though I'd never get out. It's where people go to retire. the City centre is Dead at night...completely. There's a couple of places to go in the city but not many.
It's got plenty of churches and Pokies (slot machines that South Australia is plagued with in every pub) and not much else.
Wine regions od Clare and Barossa valleys are close by and so is the beach but apart from that, Avoid Adelaide !!!
Melbourne on the other hand is amazing, I wish I didn't have to leave. Something different to do every night, museums, cafes, theatres, restaurants, little bars, big overblown places, trams, people, culture...brilliant place.
People in W.A are the best, specially the ones out in the sticks (Esperance, Broome esp).
Drive thru the tropics in wet season...now that's cool.
Take piccies of rivers of rain running down Uluru and you're in the minority.
Can't comment on the East coast, wasn't there...that's my excuse to go back !!!