A great green building manual
This book is the best book on green and natural building that I've come across. In fact it's a solid source for building knowledge in general. Many of the books out there give you a focused look at one building type or another (say strawbale) and these are great if you have already chosen that one building type. It's much more common though, to come across hybrid situations, where a broad variety of techniques or building challenges are at play. An earthship might be your best best - if you live in the southwest, but maybe not in the southeast. Each building is unique, from the site to the nearby structures and environment, the potential future inhabitants, the usage, etc.
This book gives a very grounded and informed perspective on residential building, not limited to any one form or another, but seeking only to inform the reader of the dangers and best possibilities in each situation. Snell and Callahan recognize that there is no one best or "greenest" practice. Their book educates and empowers the reader to approach each unique building as it's own challenge.
Their research into and command of the building field is a boon to anyone looking to build wisely, be that person a builder with 25 years in the field, a potential do-it-yourself homebuilder, or even someone with no building experience looking to have a home built for them who is interested in having things done right.
Also, PHOTOS PHOTOS PHOTOS! They didn't skimp in this department. This book has hundreds (thousands?) of pictures. Nearly every key point has a diagram or a photo to bring the message home. It makes the material extremely clear and easy to grasp, as well as being a valuable resource for inspiration and ideas.
Everyone has something to gain from this book, and for the price there's no excuse not to own a reference copy.