Ask HN: Do you write Runbooks, if so how?

I am just curious how people here approach documenting various operations and support aspects of their applications and systems?

I have traditionally put together runbooks for new hires or NOC/support teams with instructions how to troubleshoot rudimentary problems which may come up, how to find logs, what common failure points are etc.

How do you keep track of system accounts, certs expiration, what errors to look for in logs, how to log into certain systems etc for other to troubleshoot?