If there are a couple things that a few years of system administration should have taught you, the importance of backups and logs is one.

And when it comes to logs too frequently we worry exclusively about the what, what do I log, what format do I log it into, and so on. And in doing so we forget the importance of when (which makes good time keeping a must, and ntp worth being another of those couple things you should have learnt). A discussion about this with a colleague ended up with another commandment to be added on our dashboard: A logfile is not a logfile if it's not timestamped.
I know this all sounds obvious, but as most of the obvious things it is often forgotten.