One of the first
http://www.greenpeace.org/international/

Design Can Change is simple. It works on the belief that our industry can make positive change by working together.
http://www.designcanchange.org

From its extraction through sale, use and disposal, all the stuff in our lives affects communities at home and abroad, yet most of this is hidden from view. The Story of Stuff is a 20-minute, fast-paced, fact-filled look at the underside of our production and consumption patterns...
http://www.storyofstuff.com

renourish is a resource for the graphic design industry. When green design is usually discussed, most people think of buildings, products or even cars, but what about packaging? Shouldn't magazines, business cards, brochures and websites be green?
http://www.re-nourish.com

The David Suzuki Foundation is a science-based Canadian environmental organization, working to protect the balance of nature and our quality of life...
http://www.davidsuzuki.org/

Alex Steffen and his team at WorldChanging have created a great site for staying up to date on all of the activity on this front. (My only problem with it is how much content they create--I can't find enough time to keep up!)
http://www.worldchanging.com

http://green.yahoo.com

http://advision.webevents.yahoo.com/green/index.html

http://forgood.yahoo.com/