Which Logs/Reporting Graphs To Utilize For Which Purposes?

[ticker]

I find the choice in logs/reporting graphs a bit overwhelming and unclear. Maybe a page in the documentation that simply suggests example use cases, or tells you what menus in the GUI are used for what (ex. This page = Kernel Log, etc)

Some of the uses I'm trying to determine where to find is as follows:

Some examples of what I am trying to look for:
- WAN availability (see downtime from my ISP)
- See who is pegging my server WAN (I presume firewall log > filter by wan is the only/best way?)
- See what is slowing down my network and server (processes, connections, etc.)
- Kernel logs (I presume this is under System logs.. but General or Backend?)


And I am also very interested in hearing how you guys utilize different graphs and logs for your specific purposes.