Hey Aphrodite,
I have a lot of friends there..
Look at
http://www.altitudeapartments.com.au/
I'v been there and still have some friends there, its cheaper than a hostel, clean, very safe and mostly students. The place is not so close to uni that you can walk but there are buses that can take you.
Altitude Apartments is an example of private apartments for students, its not on campus and is a private company that has nothing to do with the uni. In Altitude you get your own bathroom to yourself and normally have a hall and kitchen. Most the time you share an apartment with someone else, each person has a bedroom and one bathroom with a shared hall and kitchen. Yes you will have to cook and clean the apartment yourself and take away food is not easy to come by in Queensland and costs alot, so if I was you learn how to cook
I also have been to the hostels at Queensland Uni and they suck. (well thats what I think) They cost about $300 a week and you have to share with other people, yes they do cook for you but believe me the food is not that great. Atitude costs about $160 and is a lot cleaner, nicer and you will alot more freedom. With the extra $140 a week you can buy better food than you'll get in the hostel too.
Anyway good luck and make sure you have fun while your there.
Cheers
Michael