You have probably seen the threads from people waiting for their Residence applications to go through when already in NZ. Nobody can be sure how long it will take for one particular case, because its progress will be along with all others being worked in rotation at the same time, and because everything has to be checked thoroughly, and the CO is always dependent on the outsiders they contact. It takes as long as it takes. But as an example, here
http://www.immigration.govt.nz/branc...ocessingtimes/ is one office's best guess, based on the average of how things have been running recently.
Your wife would not be able to work on that visa until the residence came through, and as you can see, that can take many months.
The Silver Fern Work Experience visa
http://www.immigration.govt.nz/migra...experience.htm, which you could apply for as well, once you had a skilled job, could be processed more quickly, and would allow you to sponsor your wife for a work visa. You are allowed to apply for your visa AND the one for your wife at the same time, linked with a covering letter, and the CO will work them as one case, supplying things that aren't available at first, such as your visa number, as they go along. She would be able to work as soon as your and her work visas came through.
Another thought is that, if your wife entered as a visitor and found herself a suitable job, she could apply for a work visa in her own right. As you'll see on that link, these are processed much more quickly.