Sure, you can find these several places on the internet. But are any of them written by me? Also I will tell you how much the words and phrases are really used, and how I know they're real.
chips = French fries; confirmed by seeing and hearing it a whole lot. However, the term fries is also used occasionally and it is understood what fries means.
crisps = potato chips; confirmed in the supermarket and at Takeaway's. But chips is sometimes used and this can be a bit confusing since chips should mean fries.
biscuits = cookies; confirmed at Coupland's Bakery among other things. Again, cookies can be used as well and is understood.
sweet as = excellent, cool, wonderful; confirmed by everyone using it all the time. Derived from phrases like "sweet as honey" but everyone just says "sweet as". Can be used as an exclamation or in a sentence as in "That movie was sweet as".
chemist = pharmacy/pharmacist; confirmed by exactly one pharmacy calling itself a chemist on George Street. At least in Dunedin most places are actually called pharmacies so this seems to be less widely used.
cheers = thanks, goodbye; this is an extremely common phrase. If you move out of someone's way in the street they might say cheers, or after you buy something in a shop, or just anytime really. Can be either thanks or goodbye or both at the same time.
ta = thanks; I've heard people saying this but not quite as frequently as cheers. It may just be less formal, not used as much with strangers, I can't tell yet.
keen on = wanting to or interested in; my Kiwi flatmate certainly uses it a lot but I can't figure out yet if it means "I will do X" or just "I want to do X" or I'm interested in X". I think it's more like "want to".
rooting = having sex with; confirmed by some soap opera or other [it was Outrageous Fortune]. Haven't heard anyone actually using it, but then again I haven't been talking to Kiwis about sex.
kia ora = hello, thanks, you're welcome, lots of other things; confirmed by the guide at Tamaki Brothers Maori Village, and also by it being used fairly frequently. A Maori phrase literally meaning "be well," it can be used however you want, really.
flash = excellent, wonderful, fancy; my Gender Studies lecturer used it in the sense of "I wasn't feeling so flash this morning." On the soap opera Outrageous Fortune (which is fairly unwatchable) they used it in the sense of a nice restaurant, a "flash restaurant".
entree = appetizer; confirmed on menus everywhere and by Auntie Jane. Quite confusing to Americans. What we call an entree (main dish) is called a main here. Makes heaps of sense to me (the French word entree means entry or entrance so why wouldn't it be an appetizer?).
More as they come to me.