If applying for residency, you will need police certificates from any country where you have lived more than 12 months. Most of those you can easily request over the internet, like for example the German and Swiss ones. The English one can be requested over the internet as well, but takes a bit longer to arrive. Police certificates are valid for 6 months in regards to a work visa or residency application, any certificates older than 6 months will be rejected by immigration and you will need to request new ones. Most police certificates come with a small fee.

For more information go to http://www.immigration.govt.nz/migrant/general/formsandfees/formsandguides/policecertificate/