Earthship Volumes I, II and III by Michael Reynolds
Comfort In Any Climate by Michael Reynolds
Water From the Sky by Michael Reynolds
Create an Oasis with Greywater by Art Ludwig - Excellent resource on grey water recovery.
Builder's Greywater Guide by Art Ludwig - A supplement to Create an Oasis with Greywater. This book covers permitting of greywater systems.
Earth Sheltered Houses by Rob Roy - An excellent reference for earth-sheltered houses, easy to understand and lots of practical building advice.
Water Storage by Art Ludwig - Good resource on water storage.
The Earth-Sheltered House: An Architect's Sketchbook by Malcom Wells - Considered one of the early pioneers in earth-sheltered housing. I found this book interesting, but not as valuable as Earth Sheltered Houses.
Undergrond Houses: How to Build a Low-Cost Home by Rob Roy - An excellent book, but it is all covered and more in Earth Sheltered Houses.
List taken from http://earthship.darfield.com/2009/02/earthship-resources.html
