To find articles on topics related to sustainability in architecture and green building try these databases:
LEED is an internationally recognized green building certification system, providing third-party verification that a building or community was designed and built using strategies aimed at improving performance across all the metrics that matter most: energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, and stewardship of resources and sensitivity to their impacts. (Definition from U.S. Green Building Council, the developer of LEED)
The U.S. Green Building Council (USGBC) website has a great deal of useful information including:
The Green Building Certification Institute now administers the LEED Professional Credentials and Exams. If you want study guides for the LEED exams, try this keyword search the Library Catalog: