Journey into Information Theory
khanacademy.org
khanacademy.org
[0] http://worrydream.com/refs/Shannon%20-%20A%20Mathematical%20...
[1] http://www.dotrose.com/etext/90_Miscellaneous/transmission_o...
The book itself is great, IMHO the best intro to information theory and entropy.
Not mentioned is the curious fact that there seems to have been only one independent discovery of the alphabet. All alphabets are descended from the same root, proto-sinaitic or have been made up by people who knew about alphabets (Korean). Irish runes and Khmer script thus share a common ancestor.
I am two videos in, biting my lip to not make technical comments that don't matter at this level. They do a great job of simplifying a very complex subject.