While preparing for my RTW-trip I had to check country for country about the requirements for a visa. Luckily I am a citizen of the EU with easy access to lots of foreign countries even outside the EU. Anyway there are some regulations to care about. New Zealand was my first non-European country to go to. It was not possible to get a visa waiver online. About the visa waiver you can read about the governments homepage. I had bought the expensive flights, but did not really know if I will be welcomed into the country.
In addition to that, there is no possibility to volunteer in New Zealand if you are 30+ resp. 35+, because you need to hold an open-work-visa such as a Working Holiday Visa (WHV), which is only issued to people under 30 or 35 years of age, for in New Zealand volunteering counts as work if you get accommodation and/or food.
Entering New Zealand takes time. New Zealanders are very afraid of insects from outside. Visitors have to queue for the declaration of the used outdoor items etc. If one has any, he/she will get a notice on the “immigration card” about the used items – if one is wearing them or have them in the luggage. Afterwards one has to continue to another queue, where the used item not only will be checked, but maybe also washed by an officer.