diagram

I use Microsoft Visio for most of my diagrams. Sometimes, I use Adobe Illustrator when more custom graphics are required.

I did a lot of network diagrams for two companies. I obviously can't show the entire diagrams for security reasons, but here are some examples...

Internet Diagram

This is a diagram of how the internet was connected through the firewalls. I have removed the IP addresses for Security reasons.

Internal Network

This shows how routers were physically arranged in the building.

Server Diagrams

There were many, many diagrams of the Servers, which all included Serial numbers, server names, IP addresses and pictures of the exact model of server, as they were laid out on the rack.

Procedure

Another thing I do is procedure documents. These procedures make it easy for novice users to understand how to use a new system through screenshots. In many cases, users can follow these procedures themselves without input from the IT team.