Check these sites, the first one has a wealth of free informatio and tools to help with all aspects of lean management
http://www.concreteheads.co.uk/
http://www.isixsigma.com/index.php?option=com_content&view=article&id=201&Itemid=27
Six Sigma is bascially improvement in any process or developing any process which will lead to reduce in time & money. There are 3 stages of Six Sigma
Yellow Belt Six Sigma
Green Belt Six Sigma
Black Belt Six SIgma