Nathan Shedroff has just written what is likely to become the sustainability manual for designers. Design Is The Problem is a thorough and informative survey of just about every aspect of sustainable design. It covers important frameworks, schools of thought and specific tools. It's interspersed with good examples and case studies that reveal the complexity of the issue and that force the reader to engage with the topic rather than assume simple answers, which of course don't exist. Design Is The Problem does not go into significant depth on each topic but it will give you a place to start on pretty much anything related to sustainability. Definitely an important book to have in your library.