Microsoft has a page on its web site here that nicely rounds up in one place many resources for the various Office 2007 applications.[1. Note: Beware the demo videos reference above – they require a download of ‘Silverlight’ (Microsoft’s competitor for Flash). If you don’t want to go there, I will be downloading the demo videos and will make them available as Windows Media Player files.]
Below are convenient links to free, introductory courses you can take online. Each course is approximately 30-40 minutes long.