I'm only going to provide an outline to the regions of NZ, indicating some of the highlights in each. There are more detailed guides to get you to and guide you round the trails. Support them - they do a good job. Some of the best are:

• Mountain Bike Rides 5th Edition, Kennet Brothers - from Ground Effect
• Peddlers Paradise North Island - Peddlers Paradise. Readily available in NZ bookshops
• Peddlers Paradise North Island - Peddlers Paradise. Readily available in NZ bookshops

NORTH ISLAND

In summer, the temperatures can go over 40 degrees C!

// Northland

This is the area north of Auckland. Warm in winter and hot in summer, this is the most northerly you can get in NZ. Amazingly, you can see where the waters of the Tasman Sea meet the Pacific and lift up! Rarely sees frost, so good for camping even in winter! Home to ninety mile beach, which is actually 90 km's long! Several riding options - quite a bit of forest, good road touring, and the gorgeous Bay of Islands. Many forests require you to buy a permit - cheap or free.

{pics of bay of islands, forests}

Other stuff to do - NZ's oldest houses, Maori culture, meeting of the seas / most northerly point in NZ

// Auckland Area

NZ's biggest city has over a quarter of the country's population. Home to vineyards. Riding here is mainly forests, rolling hills, flat areas and 'north shore' style parks. Marked trails in the popular forests - Woodhill forest, plus others. Lots of racing here, and lots of riders!

Go down to The Corammandel Peninsula for some remote riding.

Other stuff to do - it's Auckland! Loads! Museums, bridge walk & bungy, volvanoes in a city! Pan for gold on The Corramandel, dig your own hot spa on Hot Water Beach.

// Mt Taranaki Region

Famous for Mt Taranaki/Egmont (former is Maori name, latter is Euro name), which is 'Mt Fuji' in The Last Samuri. Folk here didn't really bat an eye lid when Tom Cruise came to stay.

Good, remote trails - Bridge to Nowhere, Bridge to Somewhere. There's a small mtb park outside of New Plymouth. If you're ever raced at Leisure Lakes in the UK, you'll feel at home here - but with hills! Lots of tight twisty singletrack!

// Volcanoes

The whole of the middle of the North Island is volcanic! Makes for some sweet rides, but be careful if you fall off - gravel rash! Remote riding. Be careful. Home of Mt Ruapehu which is an active volcano, Mt Tongariro and Mt Ngharoa.

Very good riding in and around Rotorua - it's home to the 2006 World MTB Champs. Whakawerawera forest is amazing with loads of trails - waymarked and 'local'. Home to the cat-eye moonride 12/24 hour mtb race.

Other stuff to do - Walk the Tongariro Crossing, bungy in Taupo or Rotorua, skydive, raft the worlds highest commercially rafted waterfall (7 metres high! - Rotorua) or the scary Wairoa River, Maori culture (Rotorua has a 40% Maori population), gethermal activity (bubbling mud, geysers...), spas, scenic flights, see White Island - an active volcanic island off The Bay of Plenty (you wear a hard hat and gas mask!), skiing in winter.

//The East

This area has a very high Maori poulation. The population is very sparce, and it's like going into another world round here. Life is relaxed... Some awesome long day rides - including Old Motu Coach Road, Mt Hikurangi - from 200metres to nearly 1800metres and back in a day (need to call for permission - free). Sweet.

{pics of Hikurangi}

Other stuff to do - Maori sculptures partway up Mt Hikurangi, relaxing, see where the classic NZ film 'Whale Rider' was filmed. <-- link to Whale Rider.

// Wellington

New Zealands capital, and home to loads of quality MTBing from downtown Wellington. Good, lesser known riders, such as Rimutaka Incline.

Other stuff to do - it's the capital! Museums, gateway to the South Island.

SOUTH ISLAND

The South Island is famed for it's stunning scenery and variety. It's remote and has a population of less than a million(!) - you can drive literally for hours, and only see a handful of other cars. Or even people! Very good opportunities for 'get away from it all' rides, but does get busy in summer. Autumn is a very good time to visit - the temperatures aren't too cold, snow isn't covering all the mtb trails, there are many fine sunny days, and there's less tourists around.

// The North

A suberb and very diverse area for riding. From Picton, which is the main entry point to the South Island from the North by boat, there is easy access to amazing trails dotted around the Marlborough Sounds. From the famous Queen Charlotte Walkway, to the less known Nydia track a base in the PIcton region is well rewarded.

Nelson Lakes has some multi day epics through stunning mountain scenery, whilst Nelson itself has extensive riding options from the city. Explore Dun Mountain and beyond. Check in at one of the local cycle shops for trail advice and route maps.

The Abel Tasman region is remote, and has a culture all of it's own - it's got laid back hippy community. The riding here is varied - from goldfields to steep hills.

The East Coast has some cracking trails for multi-day trips, and single day jaunts.

Other stuff to do - walk the Abel Tasman track, see natural springs, whale watching, hill walking, water taxi round the Marlborough Sounds, skiing in winter, Brewery in Nelson - Macs.

// West Coast

Famed for it's rain (over 7m a year in places!) the West coast offers a variety of rides - some very steep and hilly, others tour the vast rivers. At times you'll be taken aback by the shear untamed beauty of this region - the effect of nature's turbulent weather is very apparant. You can get weather beaten by cycle touring this sregion!

Other stuff to do - Blowholes, pancake rocks, galcier walking, scenic flights, greenstone carving, walks, Arthurs Pass railway & road.

// East Coast

A different world to the west, the climate completely changes about 70 miles inland from the west. The land turns dry and barren, the Southern Alps give way to the Canterbury Plane, and population returns!

The east coast is home to Christchurch - the South Islands largest city. The city feels small and friendly, is the home to Ground Effect clothing, and has some superb trails on its doorstep - try riding in the Port Hills, get onto Banks Peninsular. Further afield, to the north ride round hot springs, and to the south some rides around Mt Cook and Tekapo, and some riding at Naseby forest near Ranfurly - stay at Royal Hotel, run mt mtber Kila Hepi.

Other stuff to do - Hot springs, Arthurs pass, Christchurch, Akaroa. Skiing in winter.

// Southern Lakes

Your riding here is essentially around Wanaka and Queenstown. Both offer good riding - but Queenstwon is a bit more commercialised, so you can do heli biking and the like. Stunning scenery in the heart of the Southern Alps. Multi day trips, stunning road touring. Very long day ride - Percy Pass.

Other stuff to do - Milford Sound (awesome road to this place!), Doubtful sound (better in my opinion), sceninc flights, skydive, bungy, Queenstown - alledgley the 'adventure capital of New Zealand', Wanaka cinema - sit on couches, bean bags and in an open top car, and get ice cream, cakes and goodies at the interval!

// Far South

Remote riding in the Catlins, good riding round Dunedin (beer (Speights) and chocolate - mmmm), good remote touring and small mtb parks. This area can get cold and has very high winds from time to time. Stewart Island, just off the south coast has recorded winds 300km/h+!!

Other stuff to do - Brewery (Speights) and Cadbury factory, Gannet colony, penguins, remote and getaway from it all quiet retreats, visit most southerly point n NZ (can't get to it, but can see it in spring - lambing)