I spent a month in NZ in December 2006/January 2007 at the age of 30. Was one of the best experiences of my life!
My gf at the time and I rented a car and stayed in hostels, 2 nights in each city/town, and just circled both islands. We flew round trip from LAX to Auckland w/ stopovers in Fiji, on Air Pacific (a Fijian airline). On the way back, we somehow found a ticket on Orbitz that had a full 1 day layover in Fiji for the same price! Of course, we couldn't resist and had a small one day excursion cruise aboard a wooden boat.
New Zealand as a whole has the best scenery in the world, when viewing the country as a whole. Also, due to various curves, changes in elevation, and even weather (snow in winter and up in the mountains), it's best to measure driving in TIME, rather than distance. Don't look on Google maps, see two destinations are just 60 miles apart on a highway, and automatically assume you can drive it in just 1 hour. It could be 2 hours, or even more!
Here's my summary on each place we stayed in NZ, in order, from the start of the trip to the end:
Auckland - we drove straight out from the airport to our first city, but stayed in Auckland 2 days at the end of the trip. Fun city, saw a little of the beaches, general sightseeing.
Bay of Islands/Paihia - Great beaches. We took a day cruise on board a catamaran for dolphin watching and relaxing on a small island.
Coromandel - Another fun city, but be wary if you're driving and/or riding on the way there or leaving. If you get road sick from curvy roads, you better take Dramamine. Honest! I was fine because I was driving, but my gf had to take something to knock her out. Cathedral Cove has the famous massive rock in the ocean that was featured in the Chronicles of Narnia: Prince Caspian. Coromandel also has Hot Springs Beach, where there is a massive hot springs underneath the entire beach! Just look for a tiny patch of warmth at the surface of the sand, dig down with your hands, and you'll have your own private hot tub. And that water can get quite hot - like 110 degrees+.
Rotorua - Where most of the famous hot springs can be found. We toured the thermal park Orakei Korako (
Orakei Korako Geothermal Wonderland) and sat in the thermal mud pool at Hell's Gate (
Rotorua geothermal attraction and Rotorua Spa - Hellsgate geothermal park and Mud Bath Spa). No, the picture of the two people spreading mud on each other had nothing to do with my decision to go there.
Napier - The sun's rays hit the earth first each morning at Hawke's Bay in Napier. Napier also has numerous wineries that I visited (along with a few other regions in NZ). They have a beach with tiny black pebbles for 'sand'. They're very smooth and gentle, and a neat thing to see.
Wellington - The country's capital. We just stayed here 1 night to catch the ferry.
Nelson - Went to Abel Tasman park. You could take a boat taxi into the park and drop you off at several points, to then walk back to the park entrance. There's a walking path along the shore, but it's behind trees for a good part of the way. You can pick a 3 mile, 6 mile, 12 mile or longer trek back. There are beaches at each place, and if you get dropped off farther into the park and change your mind, you can wait at one of the beaches for the water taxi to make its periodic stop to pick you up. Great scenery in the park, as it's minimally developed.
Franz Josef - did the Franz Josef glacier hike. Awesome experience! Also spent New Year's Eve hanging out at the hostel with other random travelers, enjoying some Bailey's Irish Creme as we rang in the new year.
Haast Pass - The Blue Pools of Haast Pass is a neat place to stop at for 30-60 minutes (or more!) on the way to Queenstown.
Queenstown - I had my first horse riding experience with a ranch. Great views of the bay and hills from practically anywhere in the city.
Te Anau - A city right on the edge of the water. We took kayaking trips to Milford Sound and Doubtful Sound from here. The Milford Sound kayaking trip was awesome! The Doubtful Sound trip is more weather-dependent (it rained). The company we booked with had a website "guarantee" of a refund if you aren't able to kayak due to weather. But during the trip, they don't mention their guarantee if the weather is bad. You have to take a bus then a boat to reach Doubtful Sound. After riding on the boat for an hour and a half, they declared the trip 'cancelled' and at first weren't going to refund anything (to a group of about 30 people). Some people merely accepted it, while others complained. Then, the tour people offered free vouchers to those that were still complaining. Some still refused, and even showed the company where they promised refunds if the trip was cancelled due to weather. The tour company then finally reluctantly agreed to refund the money to the few that stuck to their guns, as the company originally had promised to do.
Invercargill - The very Southern tip of South Island. Could possibly take a ferry to Stewart Island, but I think we just walked around, and walked to the lighthouse at Nugget Point
SSR - Tokata Lighthouse at Nugget Point - Picture of Southern Scenic Route, Invercargill - TripAdvisor
It doesn't look daunting, but the final path leading all the way up to the lighthouse is narrow, without a huge amount of land on either side. The bridge/path does have a rope to hold on to, and you'll want to - the wind is so strong and constant that the bushes and brush actually grow at a 45 degree angle! As do some of the trees in and around Invercargill. We also saw a few penguins and there was even a beach where you could sneak up into a special viewing box to hope to see some seals on the beach about 200 ft away.
Christchurch - Modeled after the Christchurch in England, one of the more 'modern' cities in NZ. Don't know what it's like now since the earthquake.
Auckland - In addition to simply exploring around, we also visited the Waitomo Caves, which have thousands of tiny glow worms.
Remembering to drive on the left hand side of the road wasn't as difficult of a challenge as I feared. Also, New Zealand is so spread out, that once you're out of the 3 largest cities (Auckland, Wellington, Christchurch) you really hardly see very few people on the roads. Everyone is friendly, and their signage is pretty decent and easy to get around. It's a place I'm definitely going to be going back to in the future.