waitangi.com
THE HISTORY OF THE CHURCH MISSIONARY SOCIETY is very good reading. There are three sections here, the first begining at a time some 20 years before any established and welcome mission came to New Zealand, mentions some of the earlier Maori that visited overseas in pre-missionary times. It covers the genuineness of the Treaty, and then turmoil caused by the intention to 'change the rules', Maori 'movements' and touches on the wars.
Part 1 from Vol 1. C.1800 -1826. Samuel Marsden - his opposition from authority and traders - meeting first Maori. Civilization or Gospel? Ruatara, Hongi, Samuel Lee, Henry and William Williams, etc.
Part 2 from Vol 1. from 1833 - Advent of Colonists - Annexation of New Zealand - Bishop Selwyn, his travels and trials - Treaty - Colonial Encroachment and Maori Discontent - Governors Fitzroy and Grey - The Missionary Lands Question - Grey's Secret Despatch - The Maori Bible.
Extracts from Vol 2. 1862-72 - Maori Religious freedom threatened - Grog shops - Land disputes - The King movement - Taranaki War - Waitara - Sir George Grey - Pai-Marire
To first 3 chapters of Christianity Among The New Zealanders 1808 -1827 by William Williams, D.C.L. Bishop of Waiapu.