Glad to see more Poms coming to Canberra!!!
The best place to look for a house is
www.allhomes.com.au - you will get a feeling for what is available. There are areas to avoid - others have mentioned Narrabundah and Charnwood and Richardson also sometimes gets a bad press but nowhere is absolutely awful and even in those suburbs there are some really nice houses and good neighbours!
I am fortunate enough to live in the Inner North (Ainslie) which has old houses on quite big blocks. The further out you go - Tuggeranong and Gungahlin - the houses get bigger and fancier and the blocks get smaller so it all depends on what you want. Inner suburbs are generally $$$$$ and the very inner city trend for medium density living is slowly creeping outwards.