Guides for Users Migrating to Office 2010 from Office 2003
Over on the The Microsoft Office Blog there is a post that links to some migration and quick reference guides for Microsoft Office 2010 specifically for Office 2003 users:
“Whether you're coming from an older version of Office and just want to find the most frequently used commands in a program, or you're entirely new to Office and want a quick overview of how the ribbon works and how to get to the most important things, each guide provides helpful information that we've based on direct feedback from you — our customers.”
Read more and download the guides from here.
They look like a great reference to share with your end users, or to print and keep handy if you prefer paper.