The web is a rich source of information on every type of environmental issue. You may research projects here or just get ideas of what others have done to mobilize the community, organize people and resources, and act instead of talk about what we can do to literally save the world.
Here are some of the best sources I've found for content and relevance:
Overcoming Consumerism
Follow the links on this page to learn real ways how you can live in harmony with the world
Environmental Web Directory
This will take you to links to almost every environmental issue on the web.
Gardenline Trees and Shrubs
Everything you ever wondered about trees and shrubs, how to plant and maintain practically anything.