I've read an absurd number of Internet histories. And I think one of the problems with studying the history of the Internet is that it very quickly grew up and out of the small group of people who got it started, and thus writing its history must take into account the increasing number of perspectives that chronologically track its development. Also, it can be very difficult to disambiguate the history of the Internet with that of general computing. The Internet developed and continues to develop both simultaneously influencing, and being influenced by, the development of general computing. Sometimes just reading the changelog of a particular old piece of infrastructure software(BIND, AT&T UNIX) can reveal more to you than reading about the Internet specifically.
I could throw tons of links here, but below are a couple that provide detailed accounts that people may find interesting.
RSSAC023: History of the Root Server System. I'm biased because I helped edit this a little ;)
https://www.icann.org/en/system/files/files/rssac-023-04nov1...
Chapter 3 of my friend Ashwin's dissertation. It's IMO a very well written and accessible social history of the Internet.
https://www.ischool.berkeley.edu/sites/default/files/ashwin-...
Really old messages on the namedroppers ML like this. If someone could figure out how to view all messages on namedroppers I would be eternally grateful.