In EMC Console | Select appropriate forest | In action pane -> Click Collect Organizational Health Data.
This is pretty good information for any Administrator to start with, for others there is ExBPA.
Exchange Server Best Practices Analyzer (ExBPA)
Microsoft Exchange Best Practices Analyzer v2.8
http://www.microsoft.com/en-us/download/details.aspx?id=22485
Exchange Server Risk Assessment and Health Check Program (ExRAP)
http://www.windowsitpro.com/article/exchange-server-2007/from-exbpa-to-exrap.
SolarWinds FREE Exchange Monitor!
http://downloads.solarwinds.com/solarwinds/Release/FreeTool/SolarWinds-Exchange-Monitor-I.zip