HI Nithin,
If your looking for a great place to stay whilst working or studying in Sydney, you should try 'Sleeping With The Enemy' in Ultimo. They're really close to the city's CBD and all transport so it's easy to get around.
They provide long term accommodation at budget weekly rates. There's a minimum of 1 month stay, which works well as most people staying there are here for work or study, so there's a strong sense of community.
The places are really well managed, kept clean and really well set up for what you pay, they provide everything you need plus all the bills are included so no hassles. They also provide free wireless internet throughout all the houses and computers for those that don't have laptops.
I stay'd there for 2 months last year, before moving on, met some great people, but more importantly it just made life easier as opposed to getting a lease on an appartment etc. I can't recommend a better place.
check them out online....
Sleeping With The Enemy
Good Luck
Peter