1. The New Zealand Constitution is not a single document as is the case in the United States, but rather a framework of written and unwritten sources in the same manner as the United Kingdom or Israel. The main sources of the New Zealand Constitution are: rule of law; legislation from both the parliaments of New Zealand and the United Kingdom; constitutional conventions; common law; Letters of Patent; and the Treaty of Waitangi. A detailed explanation of the constitution and its various parts can be read on pp. 130-50 of Morag McDowell's, The New Zealand Legal System: Structures, Processes and Legal Theory (3d ed.), cited below at E(2)(b).
2. The national legislature is the Parliament of New Zealand. As of October 1996, it is comprised of 120 members chosen in a mixed member parliament (MMP) method. Currently 62 members are directly elected, 7 Maori seats are elected, and 51 seats are decided by electorate votes for a specific party. The parliament chooses a government based on majority of a single party or a coalition of parties. The de facto head of government is the prime minister of New Zealand. However, the executive head of the government is the Queen, with power vested in an appointed Governor General.
a. The official series for statutory law is the Statutes of New Zealand which begin in 1860 (KUQ 13.N49). Statutes from 1841-1860 appear in two works as the Statutes of the General Assembly of New Zealand (1841-1853 and 1854-1860). Statutes passed by the Parliament of the United Kingdom may also still be in full force and effect. Please see our guide to researching British Statutes. A finite list of such statutes was passed in 1988 as the Imperial Laws Application Act of 1988. An index to using the statutes is available in the print work, Tables of New Zealand Acts and Ordinances and Statutory Regulations in Force, which begins in 1985 at KUQ10.T33. For more information see J.F. Burrows, Statute Law in New Zealand, 3d ed. (2003) at KUQ1990. B87 2003.
b. The statutes are officially online here.