Unfortunately there isn't one go-to place to find all the info you need, but here is a couple of suggestions;
Get familiar with the Dept Of Conservation website Hunting section. It is not "legislation on all things hunting" per se, however it has a bit of information that will be useful to you as hunter new to NZ.
There is some info on the FSA website under the search 'hunting'
Of course, this site will be very helpful to ask questions and get pointed in the right direction, but like all things internet, don't take advice from here as gospel without double checking it. Its a good place to start though.
Bookmarks