Hello this is a bit of info I found on our immigration website, it's about a visa for youth wanting to work here for 9 months. It can be extended from what i've read but I'm not sure on the criteria for extension etc.
Basically on the immigration website it has all the information you could possibly need. You can contact them for more detailed info etc. There are other visa options of course but I thought this one was quite interesting.
Hope this helps, and good luck.
Silver Fern policies
The Silver Fern policies are designed to bring young skilled people into New Zealand. The basic requirements are set out below.
Silver Fern Job Search
The Silver Fern Job Search policy allows people to enter New Zealand for nine months to search for skilled employment. There is a limit of 300 places per year.
To be eligible you must be outside of New Zealand, be aged between 20 and 35, and meet all of the qualifications requirements, English language requirements, and have enough funds support yourself during your stay.
The application process and payment will be online. Applicants will have to provide evidence they meet the requirements to an Immigration New Zealand branch for assessment and verification. More about the Silver Fern Job Search Policy.