Two problems though. For a start it's not exactly a high traffic airport, there are no published schedules, and the air force quite like weekends off. So you need to be there on weekdays when there's something actually happening. And that's the easy problem.
The other problem is where to take them from. Allow me to google ...

A - the main spotting area. Nothing flash, it's just a couple of ruts that have been worn in the grass by the side of the road where people have been stopping for 50 years to watch planes. Somewhere along the line some of it was metalled, and you can still see the frame where there used to be a rubbish bin. Such are the spotting facilities at NZWP. Great views of the runway, the plane wash, the apron - and the security fence.
B - the end of Rata Rd. Great view of one of the holes of the golf course, but everything interesting is over the slope of a hill. And behind the security fence.
C - The golf club. They play beside the runway. It's the best place to take photos, if you can get there ...
D - The intersection of Kauri Rd and Kingsway Rd. It beats the hell out of Puhinui Rd for spotting planes on short final from East Coast Bays - it's *exactly* in line with the centreline of rwy 21 and Google Earth says the runway numbers are 600 metres from the centre of the intersection. On my ILS approaches in FS9 I've crossed there at about 300' which seems about right from what I observed there over the years. And very nice it was, laying on the grass there watching the 727 doing circuits
E - The end of Waimarie Rd. Reasonable spot, loads of off street parking, great for watching the parachute club planes on the old runway but quite a long way from and slightly below the main runway. Would be good if only it wasn't for that bloody fence ...
F - Brighams Creek Rd - nothing flash about this one, just park clear of the yellow lines and walk along the footpath until you're in line with the end of the runway, and watch the planes come in from the west. You can't shoot them on the runway because of the fence, and because the other end of the runway is over the brow of a hill.
So I'm afraid it's a bit like Hamilton and Palmy, except that the security fence is a couple of metres inside the perimeter fence so you can't even take a point'n'shoot and poke it through the mesh. ###### taggers, I hope they die horribly, slowly, and screaming.
We used to have it really good when I lived on Herald Island and was a vollie fireman there - there was no fence so you could take photos any time which I wasn't into back then, and a couple of times on fine sundays we took the truck over to the base "to visit the fire flight", never got asked any questions or for ID (we were in a fire engine, how much ID do you want ??), and we'd park up and wander out and sit at the bottom of the tower watching the planes. Happy days ...
Gary