Over on the The Microsoft Office Blog there is a post that links to some migration guides for Microsoft Office 2010:
“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.
More...