Seconded; imo this paper is a pretty good introduction to the basic concepts and motivations of information theory even today. Impressive for a 63-year-old paper.
If you want a reminder of what a stud Shannon was, remember that his masters thesis (A Symbolic Analysis of Relay and Switching Circuits) proved that you could use boolean algebra and boolean arithmetic to analyze the circuits and relays used in the telephone networks at the time. It then went one step further and proved that the inverse was also true, you could use relays and switches to perform boolean logic operations -- this was the key insight that made digital electronics possible. Not too bad for work that did not even get him a Ph.D. :)
Paper and Journal article list is here: http://en.wikipedia.org/wiki/Information_theory
Its one of the most important theories of the modern science age of the 19th/20th century