Bob, unfortunately I'm in west oz but have a look at
http://www.victrip.com.au/
This is the public transport website with timetables and route maps for train, tram (streetcars) and bus services.
There's about 40 or 50 odd tram routes covering lots of the city.
A 3-zone all day tikcet will cost $11, about $6US and gives you unlimited all day riding on the tram train and bus network.
Good value for anyone who wants to spend a day under the wires. The down side is you can't buy these tickets on a tram, you've got to go to a metcard outlet, but they are all over the place and hard to miss.
I doubt if you'll be able to see much of the entire public transport network in a day, but careful planning will show a variety of suburbs.
But, most of all, enjoy!!!