Microsoft has made available to sets of aids for helping users find their way around the Office 2007 Ribbon. The first set are the Online command reference guides. These are Flash applications that will show you the 2003 UI, allow you to click on the command you are looking for, and then show you where to find that particular command in Office 2007. You can find them using the follow links. There is no guide for Access.

Excel: http://office.microsoft.com/en-us/excel/HA101491511033.aspx

Outlook: http://office.microsoft.com/en-us/outlook/HA102221621033.aspx

PowerPoint: http://office.microsoft.com/en-us/powerpoint/HA101490761033.aspx

Word: http://office.microsoft.com/en-us/word/HA100744321033.aspx

If you prefer a tabular form showing you where which 2003 command can be found in 2007, you can find buried in Help the links to the Ribbon mapping workbooks. Those Excel files are comprehensive and can be printed (they are not the smallest one either, the Word one is e.g. 3 MB):

Access: http://office.microsoft.com/en-us/templates/TC102128601033.aspx

Excel: http://office.microsoft.com/en-us/templates/TC102128621033.aspx

Outlook: http://office.microsoft.com/en-us/templates/TC102128631033.aspx

PowerPoint: http://office.microsoft.com/en-us/templates/TC102128641033.aspx

Word: http://office.microsoft.com/en-us/templates/TC102128591033.aspx