UE members need a passport valid at least three months after leave the country. A test of financial viability can be requested, as a credit card or 1.000Z$ for staying month, in cash or traveller's checks (500NZ$ if you stay at somebody's home). It's also necessary a travel insurance.

Electricity

230V, 50Hz.
You'll need an adapter for flat shots plugs.
You'll find it at the airports and electronics shops, for 15NZ$