Here are some great sites with all the translations and common phrases you will hear and need in New Zealand.
 

http://www.chemistry.co.nz/kiwi.htm

http://www.travelenvoy.com/kiwi.htm

http://www.interlink.org.nz/projects/yo/yolyt.html

http://www.nz.com/NZ/Culture/NZDic.html
 

For our American friends, we offer these particular hints:
 

• We do speak English. Just not american english.
• We understand american pretty well - every sitcom makes its way out here eventually.
• When ordering dinner in a restaurant, the entree is the appetiser - we call the main course the main course.
• Regular coffee is getting pretty hard to find. Filter coffee is an understood term. But still hard to find.
• Iced tea isn't very common - so little need to ask for hot tea as that is the norm.
• Yield signs look and mean the same - but they say "Give Way".
• Listening to someone speaking kiwi over the PA is (I have been told) virtually impossible.
• Expect to see Coke, Pepsi, 7-Up and Sprite. Not Dr Pepper, Gatorade or iced tea. Try the unique L&P.
• Expect to see McDonalds, Burger King and KFC. Not Wendys (well there's one), IHOP, or Denny's.

In flash (tony?) restaurants it is POSSIBLE to tip but really not expected. Wages are better down here, so you should only tip if service is exceptional. 

Out of the City

In the provinces (back of beyond, past the black stump, up the boo-oy) you can expect things to be a bit quiter on the weekend. Shops may well be closed. In fact whole towns may be closed. Thank gods the pubs are now open 7 days.