Hi shazbotus. I'm from Melbourne. I went to high school in the outer eastern suburbs of Melbourne and I did my degree at the University of Melbourne. I had an ex-girlfriend throughout university who lived just off Lygon St. Also, I like trance. Sounds a tiny bit like I could be of some help
Is your internet totally restricted by the uni? I know Australia is pretty far behind in telecommunications and our ISP charges are through the roof but I'm sure you can get better deals than 100MB per month. My old ISP was Optus and it was a 3GB limit for $50 or something like that. If you're able to get an ISP other than UniMelb then I'd say it would be well, well worth it.
Cool things about Melbourne:
Trams - they'll get you anywhere you want to go, they're clean, easy to use, bloody everywhere. Since you're going to UniMelb remember that ALL trams on Swanston St will get you between Flinders St and UniMelb, so if you're at one end and want to get to the other, or to the city centre, just jump on any tram and you'll get there.
Flinders Street Station - if anyone tells you to meet them at Flinders they mean the large front steps under the clocks. It's sort of an official meeting place for people on a night out.
The Lounge - an awesome bar/lounge/cafe on Swanston St between Lonsdale and Bourke. Downstairs is a cafe, upstairs is a restaurant/bar. Once of the classiest but student-friendly, chilled out places in all of Melbourne I think. After 10pm there's a cover charge and they play some awesome trance/house/drum and bass.
St Kilda and Brunswick St - the main indy areas. St Kilda's got the beach and the esplanade, during summer this place is truly heaven with the nightlife and the atmosphere. Brunswick St has a million and one cool bars and cafes and is quite trendy and hippy.
If you can get a few mates together in the few months after you get there, see if you can go to a suburb just east of Melbourne called Kew and to the boathouse there. You can rent canoes/kayaks and go all the way up the Yarra to an outer suburb called Warrandyte. It's almost an all day trip but you see some absolutely beautiful scenery.
Melb Uni is an awesome place and I loved every minute I was there. I'm not sure what the student bar is called these days, it went from the UBar to InnU or something ridiculous and they upped all their prices and put fishbowls in the walls. I don't remember many students going to InnU after that so they might've changed it back and it might now be cool agian.
Since you'll be on Lygon St you'll be like 2 mins' walk away from uni so you won't have to worry much about travel, since walking into city centre (Bourke St or Melbourne Central station) takes all of 10 minutes.
I haven't been back home in a year since I moved to the UK but saying all this makes me really miss it. I think Melbourne is a fantastic city and you'll have an awesome time at the university. If you've got any more questions let me know, I'll check back