[collinf]

Here is a free one I really enjoyed! Goes through the history of networks and a lot of the performance tradeoffs that we must make as engineers.

https://hpbn.co/

[gerdesj]

Good stuff in there (browsing ToC). It does have a focus though (hint: there is more to the internet than www). For example, I can't find any obvious discussion about MTU.

I suggest saving this one for a little later in your journey towards networking enlightenment.

[kspy]

Great info in here, pushed me to buy the book after I got through this version, definitely keep it on my desk!