I'm travelling to the South Island to go snowboarding and touring in August, and I want to read a book about New Zealand before I go. I've got a guide book, but I'm looking for more of an insight into the place. Any suggestions?
"Be it through escapist plots, multilayered fiction, reinvented realities or character driven social commentary, the significant body of Kiwi literature presents an opportunity to learn much about the islands."
(Quote straight from the LP Guide to NZ.)
The LP Guide recommends these as top reads:
The Bone People (1988) by Kerri Hulme
The Book of Fame (2000) by Lloyd Jones
Thje Carpathians (1988) Janet Frame
Dreams Lost Never Walked (2003) Raumoa Ormsby
Electric (2003) Chad Taylor
Going West (1993) Maurice Gee
In a Fishbone Church (1988) Catherine Chiidgey
The Season of the Jew (1987) Maurice Shadbolt
The Vintner's Luck (2000) Elizabeth Knox
Whale Rider (1987) Witi Ihimaera
I feel a bit of a fraud recommending these as I have not read any of them but really enjoyed watching the movie Whale Rider! Now that I've typed them out they have whetted my appetite to sample them.Hopefully some well read posters will give you their personal favourites.

Fiction, anything by Alan Duff "once were warriors", "what becomes of the broken hearted" are worth reading for an unsanitised view of social exclusion and the bleak reality of life for some Maori people. "A land of two halves" is a travologue by Joe Bennett, an ex-pat englishman who's lived in nz for ages, I really enjoyed it.

Lord of the Rings - The Fellowship of the Ring
Lord of the Rings - Two Towers
Lord of the Rings - Return of the King
These are my favourite NZ non-fictions, epic reads

If you're into the history of the country, The 'Penguin History of New Zealand' by Michael King is supposed to be excellent.
Books New Zealand (http://www.books-newzealand.co.nz/xcart/home.php) and New Zealand Books (http://www.newzealandbooks.co.nz/) both sell New Zealand (as you may have guessed!) online.
Anything by Witi Ihimaera , Alan Duff or Janet Frame will give you a good feel of and insight into New Zealand.
Other suggested authors: Stevan Edred-Grigg (try his book ORacles & Miracles); Jenny Pattrick; Kathrine Mansfield.

I agree that the Michael King book is an excellent read. even though its a history, its easy to get into and will tell you a lot about us (that we don't even know!).
I found the 'bone people' in a backpackers cafe in China and have to say its very good, but probably hard for a non kiwi to understand. lots of Maori words and slang.
Elizabeth Knox is a wonderful story teller, but her stories aren't about NZ specifically. the vintners luck is set in Italy!
and ahh, #3, you do know those LOTR books were written by an Englishman right? In England? just checking.
For some more childlike entertainment, try some Maurice Gee - 'under the mountain' for instance. he also writes adult books - i haven't read it but 'in my fathers den' was a great movie and its taken from his novel.