For understanding computer networking, Computer networks by Andrew Tanenbaum: http://www.amazon.co.uk/Computer-Networks-Andrew-S-Tanenbaum...
For physics (though old now), Feynman's lectures: http://www.amazon.co.uk/Feynman-Lectures-Physics-boxed-set/d...
In the mean time I've heard this is good:
https://www.amazon.com/All-New-Switch-Book-Switching-Technol...
And then there's your computer network textbooks like:
https://www.amazon.com/Computer-Networks-Andrew-S-Tanenbaum/...
I have the second edition sitting on a shelf and couldn't get anyone to buy it on ebay ;)