You certainly can apply on your own. Application can ONLY be done online, and the allocated places go very quickly, so you need to be certain you have all your details, and the means of paying, right with you, so you don't waste any time.
All the details are here
http://www.immigration.govt.nz/migra.../jobsearch.htm and on the questions and answers page.
http://www.immigration.govt.nz/migra...searchfaqs.htm If you keep watching that first page, they will in due course post when the applications for 2013 will open.