I'm kind of doing the same, I'm going to Thailand on 6th september then heading to melbourne on the 17th september. The friend I was going to travel with has taken a job back home so I'm now looking at signing up to one of those Ozintro packages in sydney, then getting an apartment there afterwards.
Alison who knows us lot might bump into you in thailand Cant wait, Its gonna be one crazy year!
I just got back from an 8 month stint in Sydney so if you've got any questions give me a shout ! It is hard to get an apartment for 3 months if you're planning on renting the place directly from the agency. I found it a lot easier to do flat shares found on gumtree.com.au Also the best hostel to stay at is Wake-up, I lived there for about 3/4 months at one point. They do a winter deal where you pay for 2 weeks up front and I think its about $300 for the 2 weeks which is a good deal !
I'm happy to answer any questions !
Cassiejo- What was the work situation like out there? Did you find it pretty easy to find work and how long did it take. Thanks!
You can stay at Ashfield Manor a 10 minutes train ride from Sydney Central Station and have your own room with TV, fridge, fully furnished, etc, for $250 a week, which also includes breakfast every morning.
Another option is to join an Australian house-minding site. Most house minders will look after the house, garden, animals, etc in exchange for rent and the periods are from a few weeks to several months, as a rule.
Have a look at aussiehousesitters.com.au where you generally housesit for free accommodation. A lot of house sitters just need to feed/tend to pets and keep the place tidy.
Does this help?
I'll be heading Sydney way at some point over the time you're there too