writing documentation
I'm crap at documentation but I give it a try (I'm in the support team).
On our main document site, the top doc is the New starter guide which lists all the apps that support uses, with a 1-2 line explanation of what it does and how to install. Everyone in the team is encouraged to add new apps and strikethrough old apps when they are no longer used.
For each business group we have a page called Business Flow which starts with a "executive summary" of what that business does and how important it is (so if more than one business is screaming at the same time you know who to focus on). It then has a flow chart of the various components and how they are linked. This is invaluable when troubleshooting.
The next section is common issues - things that come up often or infrequently, or might might not be obvious. Again, everyone is encouraged to either add to this section or to tell me so that I can investigate.
And then the rest of the document is all the meaty stuff, how to install, what Devs to talk to, L2 troubleshooting, sql to run etc.
It's not perfect by any stretch but it does cover most cases. I still don't have enough time to document everything though.