Probably the best overall book about the early days of computing and the internet.

When people ask me about Xerox Parc, I always tell them about J. C. R. Licklider Lick and how he formed the ARPA Information Processing Techniques Office in 1962 and started the great research funding for interactive computing and pervasive worldwide networks that has resulted in most of the technology we use today: both via the inventions of the eventually 16 or so ARPA projects at various universities and think tanks, and by creating the next generations of computing researchers, many of whom became the founders and mainstays of Xerox Parc. The top book I recommend to read about this large process that stretched over 20 years is The Dream Machine by M. Mitchell Waldrop. It is the most accurate, has the most detail, and has the best organization and writing. He is able to admirably catch many of the most important parts of both the history and the spirit of the many headed research and engineering processes that together created our interactive networked information world.