Hi mooreaz,
huckster is, as usual (!), spot on. The official sites and employment agencies are definitely the best way to do this. I spent a year out there about 10 years ago. It was fantastic and I would recommend it to anyone, but then I was single and so without the responsibility of a family etc!
I would definitely take the time to talk to as many people as possible about the best areas for your type of work - and I would definitely try and arrange some interviews while you're over there. Failing that, I think the NZ embassy still do job-fayres where you can talk to prospective employers face-to-face. It's much easier to go with a job offer than not (statement of the bleedin' obvious!)
But the hardest bit of all is the distance and the psychology. The thought of having to fly back to the UK to see friends and family get married, missing nephews' birthdays etc is much harder than you can imagine. It's often the little things you take for granted that you miss the most.
Having said that, I'd still recommend it without hesitation - the people are so friendly, the lifestyle and attitude is spot on and the scenery is simply breathtaking. Like anywhere, it's very much what you make of it and NZ will always have a very special place in my heart, even though I was only there for a year.
HTH.
PS: In terms of pronunciation, 'wh' is a 'f'! I have a maori dictionary somewhere, I'll dig it out if you're interested... ;o)