So I've spent most of the day rewiring a building. The building is over 100 years old, has three floors, two separate Internet connections, and cables galore, none of which go where one might expect them to. I had planned to rewire it over a coming weekend since we are switching the building to a single high-speed cable line, but since one of the incoming DSL modems died yesterday (they weren't set up to fail over; they were completely separate lines serving two programs in the same building), there was no time like the present.
I still have lots more work to do to get this building functional, so I won't say much more than this: go forth and document. Go now. Find students and make them do it. It's a great activity for kids in detention. Know where every cable goes, where every switch is located, which ports correspond to which jacks, and which jacks correspond to which computers.
Do it in a way that your successors can figure it out and those with whom you work can share and update it as time goes by.
And while you're at it, can you share it with us? I don't need to see your whole network scheme, but good templates that are easy to understand are hard to come by. If you have something that works, share it. Please? Because as I accidentally switched the functional side of the building this morning to the new service but left the dark side of the building dark (since no one actually had a clue where any cables were strung 20 years ago), I realized that some documentation might be a good idea. My high school and middle school networks are at least tolerably documented, although someone without prior knowledge of the system would be hard-pressed to piece everything together. But some of these older elementary schools, in which computer labs have just sprung up, ad hoc, are a completely different story.
So share what you have, OK?