I too found much interest in the Maori lifestyle and warrior arts after seeing "Once Were Warriors" but have found limited resources in terms of the Maori Stickfighting art of Taiaha. I know it was not only used as a means of self-defense but for performing and ceremonial rituals. Here are 2 links that may interest you:
I am also very fond of the TaMoko, the art of skin carving.
Good luck in your research and please post further information you find.