Volcanoes of Auckland: The Essential Guide, by Bruce Hayward, Graeme Murdoch & Gordon Maitland (Auckland University Press)
Every household in Auckland should have a copy of this book, and every visitor to Auckland should at least take a look at it. The geology of Auckland and its volcanic origins are fascinating, and this book explains the history and science in an accessible but authoritative way, with stunning photographs and clear diagrams. I thought I new quite a bit about this, but I've learned so much more. For instance, I didn't know that 8 of Auckland's volcanic cones have water reservoirs buried into their crests, and that some of these will soon need to be replaced, or that each of the volcanoes has only erupted once, except perhaps the most recent: Rangitoto, 600 years ago. This means the next eruption will be somewhere where no volcano has previously existed...