For active volcanoes, we have Ngauruhoe, Tongariro, and Ruapehu in the centre of the North Island. Taranaki is dormant, not extinct. Some volcanoes in the Rotorua area have had recent eruptions.
White Island and Mayor Island are either active or dormant. The Kermadec volcano/es are definitely active, as is Erebus.
Otherwise there are hundreds of dormant volcanoes. The Auckland Volcanic field has produced about 50 vents in the last 250 000 years. The last of these (Rangitoto) about 600 years ago. All the South island volcanoes are extinct.
See the related link below for more details on the volcanoes of New Zealand .