The New Zealand Electronic Text Centre (NZETC) of the Victoria University in Wellington is publishing over 1,000 New Zealand books in electronic format. The ebooks are published in ePub.
NZETC offers an archive of New Zealand and Pacific Islands texts and heritage materials. They'll keep on expanding the archive and also work with partners in the the cultural heritage and epublishing sector on a variety of digitisation and digital content delivery projects.
You can find the books here:
http://www.nzetc.org/. They have a blog too, here:
http://nzetc.blogspot.com/.