In an effort to help the less technical community understand what Wikimedia Foundation's systems administrators do, Sumana Harihareswara wrote some very interesting blog posts. They're interesting to technical people too.
- From duct tape to puppets: How a new data center became an opportunity to do things right
- How the Technical Operations team stops problems in their tracks
It is particularly interesting how she expresses the value of what we do to the Wikimedia managers and donors. There's also some information in there about how Wikimedia Foundation Ops uses Puppet, Nagios, and Ganglia.
They're both worth reading. Enjoy!