Hotels/Info in Melbourne, Australia ?

I'm travelling to Melbourne in July! (its ok i love the rain, and i love the aussies :) What site can I find SUPER cheap hotel prices other than exp/trvlocty/orbtz/hotels.com any non-mainstream sites you can share with me? I considered couchsurfing, but ill be sharing a hotel with my friend. Also, whats the area like in Mel? Aussies help me out! Should I stay in Carlton? Is St. Kilda far from city center? Thanks!