Hi Calif408,
I guess it's the huge reply that would be required to satisfy your questions regarding your backpack trip
NZ would certainly lend itself to hitching around the country.
We have plenty of hostels here.
If you made your start in Auckland, the city has quite a few hostels, and it does become a stepping stone by either meeting others that are travelling or by finding the best destinations for backpackers.
There are few roads that head north/south so the chance of getting a ride is pretty good. You just can't hitch on the motorways, so initially getting out of the city can be done by standing at an on-ramp.
As to where to go, check out google, just put "
nz backpackers" in search and you will be presented with many backpacker lodges.
The cost of living here should make your dollars last you a while.
Hope that helps.