Hey mate, I have a slightly different perspective from PFOG, who's been in the game for far longer..!
Drumtek is definitely one of the better shops for general expertise, teaching and so on. If you're out closer to where I am, then Drum Power in Bayswater isn't bad either - the guys there are very friendly and helpful at all times.
Can't help you with a teacher, unfortunately, but PFOG has that covered pretty well.
In terms of picking up with a band and beginning to gig... I'm afraid I have to point you toward a local forum, www.ausband.com.au
- the guys there are mostly from Melbourne and always helpful. And they'll steer you toward good gigs to see too, I'm sure. Most of the up-and-coming local music seems (to me anyway) to largely be on display in venues such as Revolver, the Northcote Social Club, the Esplanade Hotel, the East Brunswick Hotel and the Corner Hotel.
Agreed with PFOG on the rehearsal space thing. Expect to carry your own gear everywhere, and have to set up and tear down between each rehearsal.