hmmm I am in Brisbane so can't help a lot. But Cairns is definitely a beautiful spot for tourists. The Kuranda train is one to see. It is a scenic ride on an old steam train. Lots to see there. Bring some winter clothes, it's our winter here so a bit chilly. :-) Victoria is even colder.

Hey!

I'm from Melbourne so I can give you a couple of ideas for what to do while in town.

Best sights to see/activities in Melbourne that I can recommend are:

SPORT:
Go see a game of AFL - its nearing the end of the season and seeing a game between two of the big teams at the MCG is a must do! teams to see to ensure your going to a good match include: Hawthorn, Geelong, Sydney, Collingwood, Essendon, Fremantle, Richmond. If you are unsure about the game check out this link http://www.youtube.com/watch?v=wc0dZdorN7s

ART:
For the next month or so the National Gallery of Victoria has an exhibition of paintings by Monet, I went the other wek and it was quite good, the permanent collection is not bad either.

Melb's has a pretty descent street art scene too and you can do guided or unguided walking tours of the city's laneways - there is plenty of info on trip adviser

There's also always good stuff on at the art's centre (right next to the gallery) and the museum aswell.

Music:
there's always good music on if your into seeing a gig, Melbourne is full of cool venues like the hifi bar in the CBD or the corner hotel in richmond or at bigger venues like festival hall, check out beat magazine or beat.com.au to see whats on when you are here.

General sights to see:
Flinders St Station
St Paul's Cathedral
Federation Square
Eureka Tour
Shrine of remembrance
Royal Exhibition Building
Royal botanic gardens

If you are willing to drive out of the city to see some sights you could also check out:
The Great Ocean Road - coastal drive with some awesome scenery
Mt Dandenong - not really much of a mountain but has some nice pubs and towns at the top and a good view over melbourne
Puffing Billy - old school steam train htat runs near mt dandenong
The wineries in the Yarra Valley - about an hour and a bit out of the city to the east but very nice, you can book tours etc just check out trip adviser again!

Bars:
heaps and heaps of bars/clubs and nightspots in melbs but a couple of my faves include:
Blue diamond on queen street
sentido funf, the black pearl and kodiak club all in fitzroy
Fathers office on little lonsdale street

other things to do:
Stkilda is a beach side suburb just outside of the CBD that has plenty of bars restaurants and freaks galore, also has an amusement park Luna Park, pretty small but worth checking out.
Astor theatre - old school cinema on chapel st that show old movies, everything from disney movvies to 80's classics to black and white movies

As for food there is plenty to see and plenty to stay away from.

The Queen Victoria Market just north of the CBD is worth going as a tourist attraction in its own right but also has great food to try
Another good market, moore food based is the Prahran market (again on chapel st).

Restaurants are everywhere so I wont bother going in to detail, just get in to the city and start walking the laneways, make sure you check out china town on little bourke street!

Coffee is a big deal in Melbs there's a lot of great places and a lot of rubbish ones so make sure you check out:
Brother Baba Badun on little bourke st
Auction rooms on errol street
Patricia Brewers on the corner of little bourke and little williams st

Chains - there are a number of "healthier/gourmet" fast food chains that you can get healthy choices from if you pick the right things on the menu:
Grill'd - burgers
Schnitz - chicken burgers and wraps
roll'd - vietnamese rice paper rolls

I hope this helps, have a great trip!