You should check out "expats in New Zealand "yahoo group. I can't post an url because I am new to this board. But its a good group with alot of activity(people who have immigrated, or are in the process, or inquiring). Do a yahoo search, it should come up. Also "Immigrate to New Zealand" search should bring up alot of government sites/ job sites etc for NZ. Lots of links.
There is a new site that is quite controversial- "Expat exposed behind the hype of New Zealand". It can get pretty hostile because it is a site dedicated to informing or sharing the pitfalls immigrants find having immigrated there. So some Kiwi's take great offence. But it does give some insight and its important to hear how others have fared in their dream of living in NZ. Two sides to every story and all that. Better to consider it all in the UK and not once you are there. You can read without having to register at this site.