There are two main legal publishers in New Zealand (Thomson Reuters and LexisNexis), and both provide electronic versions of the statutes on their databases. The statutes are compiled (include all amendments) and very current. They also provide added value services such as commentary, legislative history, and links to associated case law.
Current legislation provided free to the public by the Parliamentary Counsel Office.
Older bills are available in paper copy on the 7th floor of the Central Library:
To check where a Bill is in the legislative process, you can use the Parliamentary Bulletin (electronic copy provided by the Parliament website).
Acts as originally enacted (without amendments or indications of repeal):
If you cannot find the statute in the databases above, you will need to turn to the paper copy.