Two things. If you get offered a skilled job which qualifies while your student visa is still valid, you can apply for a work visa, e.g. Essential Skills, or Work to Residence (which they are now calling a LTSSL work visa).
If you are doing a course that is of the standard to qualify, after it finishes, you can get a Post Study Work Visa (either sort)
https://www.immigration.govt.nz/sear...%20work%20visa, which allows you more time to live and work in NZ, to look around and find a job that will let you apply for a work visa and/or residence.
Edited to say, I've just realized I answered this to you before on another thread.
http://www.enz.org/forum/showthread....145#post541145