First off, you might want to check the Magic Store at Southgate (Southbank)
http://www.themagicstore.com.au/
Every 1st Monday of the month there is Magic Mondays at Dante's in Fitzroy, you can get info when you visit the magic store.
Every 2nd Monday of the month there is the Australian Society of Magicians (ASM) meeting at the Swiss Club in Flinder's Lane (CBD)
Every 4th Monday there is Mitcham Magic at the Mitcham RSL, once again info can be obtained at the magic store.
If you want updates on what's happening around Melbourne, you should check out
http://magicmornings.com.au/
A weekly magic oriented talk show thingy hosted by our friendly magic store people.
Hope this helps, and look forward to seeing you around.
cheers