These twenty video lectures by Hal Abelson and Gerald Jay Sussman are a complete presentation of the course, given in July 1986 for Hewlett-Packard employees, and professionally produced by Hewlett-Packard Television.
I take you on a simple stroll through Lisp's basic constructs and then ramp up quickly. You'll see Lambda expressions, recursion, and macros. This quick tour should give you an appreciation of Lisp's productivity and flexibility.