It is difficult to write objectively about the country you call home. Having said that, New Zealand is a wonderful place to live and travel in. It has beaches, mountains, forests and lakes that will appeal to the adventurous. It also has friendly people, some nice towns and cities and the rich Maori culture.
As in any country, I feel the cultural shows for tourism hardly give you a feel for a culture. If you want to experience more of the Maori culture it is possible to stay on a marae, or the site where Maori and invited guests congregate for special events and ceremonies. Check your guidebook for maraes that allow guests.
Unless you are only heading to Queenstown, summer is the best time to tour New Zealand. As New Zealand has a maritime climate the weather is very changable, but December to April usually offer the best weather.