My first resource for scenarios comes from scenario thinking. It says it is the world's No. 1 open community on scenario thinking and scenario planning where one can publish scenarios, and reflect on the planning processes and also share online resources about scenario planning in a democratic manner.
http://scenariothinking.org/wiki/index.php/Main_Page

My second resource comes from Organisation for Economic Co-operation and Development (OEDC). They talk about seeking more efficient ways of maintaining established practice, rather than about shaping the long term. It discusses how to develop scenarios and use them to address the challenges confronting policy and practice.
http://www.oecd.org/document/42/0,2340,en_2649_35845581_36507370_1_1_1_1,00.html

My third resource comes from Global Business Network. It explains the history of scenario thinking. It also says that scenarios are tools for ordering one's perceptions about alternative future environments in which today's decisions might be played out. Scenarios resemble a set of stories, written or spoken, built around carefully constructed plots.
http://www.gbn.com/AboutScenariosDisplayServlet.srv