Lakoff and Johnson are the authors of an outstanding and accessible introduction to Conceptual Metaphor titled Metaphors We Live By. It belongs on everyone's Book List.
George Lakoff is at Cal Berkeley as is the Conceptual Metaphor home page containing the Library Of Metaphors: cogsci.berkeley.edu 
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Mark Johnson is at the University of Oregon as is the Center for the Cognitive Science of Metaphor Online: philosophy.uoregon.edu .
I'd recommend Women Fire And Dangerous Things by Lakoff instead of Metaphors We Live By. It develops the same argument much further.
See original on c2.com