Question

In learning about troubleshooting network congestion, I need help with identifying metrics that can be used to determine issues with network congestion or bottlenecking of data on a network. Then in your own (easiest to understand/beginner level) words, identify how these metrics can be used to diagnosis and resolve network congestion.

Answer 1

So you need to know key metrics that can be used to troubleshoot your network. You can see real-time values of network performance, like Network Bytes Received/Sent per second, by using Windows Resource Monitor. You can open it in Windows Task Manager (Ctrl+Alt+Del) in Performance tab. Click "Open Resource Monitor" and go to "Network" tab. I guess it will be helpful for beginner.

Answer 2

First I would ping the server you have trouble communicating with. 
Second, I would run a traceroute the command is tracert server-name this will give you an idea on where the bottle neck might be,
Third I would check the error logs in both WS and Server. 
Fourth I would check logs on the switches/routers if any. (you might need to enable logging for a short period of time since it takes a big hit on performance.
Use Microsofts Network Monitor and see if you see any abnormalities.