Hey sorry I didn't get to this thread sooner.
You could look up bunch of hotels in the area and send an e-mail about yourself with your resume attached. I think if it's done professionally it would be a great way to get your foot in the door. Make sure you remember the name of the person you e-mailed then contact them personally once you get to Sydney either by phone or in person. Many of the hotel's websites might also have a section detailing position vacancies.
If that fails and you want to go for a more broad approach, two of the main jobs sites in Oz are ww.mycareer.com.au and www.seek.com.au
Or go to google.com.au
and do a search in Australia for hospitality jobs or employment agencies.
As for finding somewhere to live maybe have a look at the notice boards at a nearby University and see if someone else is looking for a room mate. If not I'm sure there will be papers and such you can use. I'm not from Sydney so my experience as to where you should live is limited. I can tell you from my own non-Sydney experience living in an inner city apartment can be surprisingly cheap if you share with a bunch of people.
Once you arrive and chat to some random people I'm sure you'll get a feel for it really quickly.
Also be sure to come down to Melbourne so I can show you around.