I did a whole stack of servers using SNMP based monitoring years ago and it was amazing. I could see loads, memory stats, NIC utilisation, disk space, and all sorts of other things. I tried Cacti and Icinga and settled on the latter but they are all fairly similar. Once you are generating the data you van do whatever you like with it, so monitoring load attributable to which actual executable is definitely manageable. It is also handy for getting notifications for something being down, losing stability, or just being out if whack.
I don’t know about videos but having a look at the OSI model is a good way to start. It covers the abstract framework for packetizing data including things like the distinction between hardware and software, envelope, encryption, application layer stuff, the whole shebang. The cool thing is by going hardware, network, application you can see where responsibility are and it helps you understand where things can go wrong.
If you are interested there are plenty of CCNA style courses available on the internet, licit and otherwise, and they go into more depth, and the same applies to RHCE/RHCSA material. The training for certifications like that covers what you want to know but also puts it in context, and again licit and otherwise sources are available.