After travelling Australia a few years back I felt it would be of interest to anyone doing the same to get a few tips along the way.
Things to take:
Backpack 65litres maximum.
Pack heavy items to the center and roll clothing instead of folding (prevents creasing).
Take a travel towel not an ordinary towel they are smaller and dry quicker and pack easily.
Take a universal bath plug, some hostels have baths and no plugs.
Take one plate, bowl and knife and fork set (you can get from any good outdoor store) hostel kitchens can get busy and its difficult to find dishes.
Take a sarong, sometimes when away for a long time and your sharing a room with 10 others you just really want some privacy, a sarong can be hooked up on the bunk so you can hide for a time.
Wear your hiking boots to travel in, take some good walking sandals and a pair of cheap flip flops for hostel showers (verucas and hygiene, some travellers do not believe in).
A rubber doorstop (can be bought at some outdoor stores) is a worthwhile safety device especially for women. If your hostel door doesnt quite close or you are in an unsafe area, it prevents people coming in during the night. Again, this is just a precaution, you probably wont need it.
Take a small torch.
What not to take:
Dont bother with a pacsafe, these wire safe things that wrap around the backpack for security. They can easily be clipped with plyers and to be honest most places you wont need them and they are costly.
Waterbottle can be bought there.
Loads of clothes - you can easily wash, or buy when over their, dont over pack.
Remember Australia will have practically everything you need, and often its cheaper so dont pack for England.
Advice: Listen to other travellers recommendations on hostels, they often know the best places to go.
Places to visit and stay:
The Sanctuary at Mission Beach is the most beautiful place to stay. In a hut in the rainforest with a beautiful chilled out peaceful lodge to eat in, a divine organic food. The person who runs it does yoga classes and its so quiet. If you need some peace and quiet this place is the place to go to read a book overlooking the forest and ocean.
Cape Tribulation: Stay at the Cape Tribulation Beach house, it is inexpensive, in the rainforest, right on the beach and also is very relaxing. A great outdoor bar under a canopy of wood and trees, chilled out, not a party atmosphere just really really chilled out.
Northern Territory: When in Darwin book a trip to twin falls, where you swim a couple of miles down to the most scenic place. It is like a vision from an Indiana Jones movie. Take flip flops for the walk to the water, the sand can be extremely hot to walk on.
Melbourne: Visiting William Rickets sanctuary, have a bite to eat at the place that sells english scones with cream and strawberry jam, so delicious. Go on the train through the dandenongs and dangle your legs over the side like a child. Much fun to be had.
Go to Sydney during January I think thats around the time of Australia day, their are many free ourdoor events, Opera, ballet, jazz, its a wonderful time to sit out under the stars, watching fruit bats fly overhead, drinking fine wine and eating strawberries and meeting new people.
When in Sydney get a share house, I stayed in one ran by the International Travellers advisory service, I met some really nice backpackers and we had much fun over Christmas period and new year.
You have to experience new year at Sydney harbour, get yourself a foldy chair from a camping shop though and find a spot early afternoon.
When in Perth take a trip to Freemantle on a weekend a brilliant market and great atmosphere to people watch.
Also try out rottnest island for the day, dont bother staying over, I did it was dull and creepy I stay in the old barracks on my own eek! scary.
Stay in Tasmania the most cleanest air ever. Wineglass bay is a must for a visit. Dont do Port Arthur, unless your into history, its scary, creepy and negative.
Places to avoid:
Adelaide (a dull city)
Brisbane - okay if your into partying its just another city to be honest.
Newcastle - much like newcastle upon tyne (my home town) but before industry ended its dull and dark.
Im sure I have lots more to add, but thats all for now.
Enjoy your travels,