The most important thing to search engines is the number and quality of incoming links to your site. Three sources for these are similar websites, link directories and press release syndication services.
People will find your website on search engines by searching for specific keywords and search phrases. Once you have determined which keywords you want to focus on you can optimize specifically for those words both by modifying your content and by making technical changes to your website.
The three best general interest social news sites are Reddit , Digg , and Stumbleupon . The best social news site specifically for environmental issues is Hugg.
For a list of other social news sites that can be of use to nonprofits and foundations, please visit http://thehatchergroup.wordpress.com/2008/05/12/social-media-sites-of-value-to-nonprofits-and-foundations/
Social News - Social news refers to websites where users are able to vote individual content submissions up or down. Anyone can submit content, and anyone can vote.
Social Networking - Social Networking refers to websites where individuals or organizations create a profile in order to make connections, share links and communicate.
Social Bookmarking – Sites where users can bookmark websites, tag them with keywords and search for other sites by keywords. Creates a “folksonomy” in which people, rather than editors, are choosing how content is labeled and discovered.