I just ran across the whitepaper on MIcrosoft's website called "Statistics Used by the Query Optimizer in Microsoft SQL Server 2005" available at: http://www.microsoft.com/technet/prodtechnol/sql/2005/qrystats.mspx.
If you have every wondered about how statistics are used inside SQL Server, you should read this paper.
About bradmcgehee
Brad is SQL Server trainer, writer, speaker, and consultant, and in addition is the Director of DBA Education for Red Gate Software. He lives in Hawaii.