On-line application is better 'coz it's cheaper & faster. You should know first if you qualify in points based on your spouse & your qualifications. You could register at:

https://www.immigration.govt.nz/secure/default.htm

In my case, I applied on-line and my EOI was approved and I was already invited to apply but i have to turn it down due to some reason like: going to Beijing for the interview and other expenses which i don't prioritize at the moment. i paid the EOI application on-line using credit card including the preliminary NZQA assessment. i believe master JEDI had also gone through this process.

My friends who are now in NZ regretted their use of consultants 'coz it seems that they just padding their fees in every step of the process and you'll be obliged to make use of their mailing address so they can hold your documents once you miss payment, or you cannot follow-up directly to the NZIS.

My 2 cents...hoping other succesful tsikoteers in NZ could enlighten you more on this..

Good luck...