I'd love to research each thing on its own independently but it's so hard to come up with the list without already knowingI would recommend examining from different perspectives: network activity or options at each layer (wireshark), browser activity (firebug, debugger, or read the code), OS activity (debugger, or read the code), program activity (debugger, or read the code, or learn various system monitoring tools like filesystem monitors, kernel or library-based tracers, etc), virtualization systems (their hardware and network emulation), network systems (proxies, load balancers and caches of all configurations) security systems of all kinds. You are right that there is probably no holistic resource, because the question is sort of ridiculously specific.
