Since no one answered this, I can provide some meagre suggestions, but I wouldn't know if these are "definitive." I haven't read these books, but I have the list for a day when I have the time to read them.

Katie Hafner, Where Wizards Stay Up Late: The Origins Of The Internet

Steve Ballmer, Robert X. Cringley, Nerds 2.0.1: A Brief History of the Internet

This list of resources or this one might help.