Sorry about about that pressed enter before writing it all opps!
So Top half of oz - May-October
Bottom half of oz - October to May.
Best way to travel oz is by camper van for sure, you get to see the best sites, dont have a time limit as such and the cheapest way. Me and my partner did it this way and saw the best things, met the best people and can do it cheaply. Now i think you are traveling on you own??
If so its best to look in hostels for people that have extra room in thier camper vans, plenty of people willing to do this - cheaper for them and good to get extra company on the long drives!
There are plenty of free parking/camping areas all around ozzie to stay at, which makes life soo much cheaper, these are few and far between in towns but once you get out of towns then can stay for free in many amazing places. For this get the camps 6 book (the backpackers bible) tells you all the free places to stay and maps to get around soo easy!
You dont really need a lot of money in west ozzie as most of the attractions are free. However when going over to the East this is where you spend a fair bit of money, attractions cost (unless you go inland a bit to the beautiful National Parks) and there is a lot more party atmosphere, making you spend more on the alcohol (which is expensive)!
If you really want a job then you will work hard enough to find one earning av $20-$25 hr over in west, in east you will not be looking at such money(so I would say try get a job over here, save so much more) There are employment agency's all around oz that help you find short terms jobs, which suits backpackers!
If you work for your second year visa make the the place has got a qualified ABN number and as far as I know if they have that then you are more or less guaranteed your second year.
Sorry but cant help you for NZ haven't made it there as of yet, but defos do get over there as I have heard form many many people thats it is just stunning (and seen many pics).
Oz is expensive but if you are carefull you can make your money last e.g drinking cheaply, dont eat out much, travel the cheapest way possible (camper van!), when working work work work as many hours as you can in short space of time then enjoy what you have earnt!