Single bed room accomodation in Australia

Hi,

I am booked up to go to australia on in November. I plan to stay in a
hostel for the first week and in that time first myself a more long
term accomodation solution. I was hoping that I could find a single bed
room in a house shared amongst other travellers. Is this pretty much
the most common traveller scenario?

Also ... How much is this likely to cost per week / month?
How much, if any, notice do I need to provide before I move out?
Upon arrrival (Sydney), where would I enquire about this?
Is there anywhere I can look up on the web that will provide me with
any information on this?

As you can maybe tell Im very new to this idea so any basic help would
be much appreciated. Thanks

Burnsy