Here are some organisations that can help you when you are looking for work.
Careers New Zealand is New Zealand's leading provider of independent career information, advice and guidance. They aim to provide all people living in New Zealand with access to the best careers information, advice and guidance to achieve their life goals.
Student Job Search – Job listings for tertiary students
Work and Income assists all people looking for work. If you are unsure about what to do or where to start, Work and Income is a good place to start
Work and Income also provides Youth Transition Services, which can help young people into jobs or training
The career services at your school or university can usually help you with things like CVs and cover letters.