When you are doing the leg from the Gold Coast to Sydney, it is a good idea to plan on doing it non stop.
Upon exiting the Gold Coast Seaway head ESE straight out to the edge of the continental shelf where you will pick up a current that will carry you south at 3 to 5 knots. I think it is there most times of the year but do some research to find the best times.
You should still be able to see the coast from there all the way down and have good VHF radio contact with the various Marine Rescue Stations. Maintain a good radio watch and keep your scheds. They get very annoyed if you don't and if you do not let the last station know when you transit to the next station coverage area.
If you hug the coast on this leg you will be pushing into a backwashing current and the entrances are not user friendly, most of them being "bar entrances". Scary in calm weather and terrifying in rough weather.
I also suggest you have three aboard from the Gold Coast onwards. It is a big trip you are planning.
Cairns to the Gold Coast will be a good shakedown cruise for you before the big blue briney part further south.
The Queensland coast can be done in fairly easy, roughly 50 mile daily runs with plenty of island anchorages and ports to enter.
My suggestions are:-
Cairns to the Frankland Islands F Is to Mourilyan Harbour (Hole in the Green Wall) M Hr to Dunk Island avoid Hinchinbrook Passage and go D Is to Palm Island (aboriginal reserve so you can't land, anchor at the south west end in Challenger Bay) Palm to Magnetic (good for food shopping instead of Townsville).
From here you have a lot of easting to make before you get to the Whitsundays so make sure you have plenty of fuel on board.
Get an early start or slip across to Cape Cleveland the afternoon before, then, avoiding Cape Bowling Green, go to Cape Upstart and anchor in close to where the houses are. Then Upstart to Bowen, Bowen to Airlie or Hamilton Is, from there to Mackay or Scawfell Island from there to Digby Is (an almost land locked anchorage) then nobody ever misses going to Middle Percy Island.
From there put in a big day and get to Pearl Bay or even Port Clinton. This part of the Shoalwater Bay Military Training Area so check on the radio with marine rescue to see if there is anything going on. From there to Great Keppell Island but the resort is shut down so you could go into Rosslyn Bay where there is a great marina.
It would be a good idea to avoid going down the Narrows unless you have a deal going with the sand flies, so I would go to Cape Capricorn and the next day on to Pancake Creek or Lady Musgrave Island. You might like to go into Round Hill Creek at the Town Of 1770 but check with Marine Rescue for the bar conditions.
Next stop is Bundaberg, highest volume port of entry in Australia for international cruising yachts and my home town. It has three marina complexes one of which is in the heart of the city. Excellent facilities here for anything to do with yacht repairs etc, so you might like to give me a ring if you need a hand with anything or even to just say gidday.
From here to the Gold Coast is easy stuff via the Great Sandy Straits, Mooloolaba and Moreton Bay.
If you are not going to be spending a couple of months exploring the Queensland Coast, apart from the appropriate charts, the only publication I recommend for Qld is the government published "Maritime Safety Queensland's Beacon to Beacon Directory" for $40. It has everything need for inshore navigation between Gladstone and the Gold Coast and more.
For longer term cruising there is "100 Magic Miles of the Whitsunday Coast" and Noel Patrick's "Cruising the Curtis Coast" (Mackay to Bundaberg).
Considering the yacht is only a 30 footer, have you considered having it trucked to Melbourne. If you take the costs of sailing her down and time off work etc, you may find it more economical.
Cheers Cisco

PS This could be a good link.
http://www.boatbooks.com.au/