are you asking about index futures or the december rendition of futures on individual stocks ? if the later I know nothing about them but I am sure the futures exchange has ample resources. http://www.cbot.com http://ww.merc.com
Stock futures are basically what the name implies a contract to deliver a certain amount of stocks in the future. Not a basket (index) but a single stock, for example NT. Similar to options they are based on a set amount of stocks (100) and have certain margin requirements like futures set by the exchange. They are already trading in some mkts (eg Canada, Spain) but havent yet been approved for US by the SEC although they are going through the pipeline. If you want to find out more about how they are being traded right now take a look at: http://www.me.org/en.ssf.html and http://www.meff.es/ing/indexi.htm there you can see how those countries and exchanges handle the trading of single stock futures