answer the opsreportcard questionnaire, AKA the "limoncelli test"
Tom Limoncelli is the reknowned author of Time management for sysadmins and practice of network and system administration, two excellent books I recommend every sysadmin reads attentively.
He made up a 32-question test (PDF, website version on opsreportcard.com or the previous one-page HTML version) that covers the basic of a well-rounded setup. I believe we will get a good score, but going through the list will make sure we don't miss anything.