Hi Guppy
The first thing to make clear is that your other half isn't going to become a British citizen without completing a five year residence requirement, and having no time limit on her stay at the end of that period. So, given your stated plans, I think you're looking at the long haul, rather than the short... (The five year requirement is reduced to three, if you're married on the day of application). Anyway, have a look at Guide AN(NEW), which you can download from
this page on the IND website.
Before you come back from NZ in 2008, she'll need to apply for an unmarried partner visa - information
here, on the UKVisas website. In order to qualify, she'll need to show that the two of you have been living together in a relationship "akin to marriage" for two years. So start collecting as much documentary evidence as you can to support this - bills, accounts in joint names, etc etc.
Once the UPV has been granted (normally for two years), and she's back here, she'll need to apply for indefinite leave to remain (ILR) up to a month before the visa expires. Then she'll be here without a time limit, and about three years later, she'll have done the five years necessary for naturalisation.
Hope this helps.
