Free is always a great price, but this time, free is not only a great price but a great product. A company, Mouse Training, has release its training manuals and Quick Reference Guides for Office 2007, Office 2003, Office XP (2002) and Office 2000. The materials include Word, Excel, Outlook, PowerPoint, Access, Project and Visio.
All of the documents are in pdf format. To get them, go to http://www.mousetraining.co.uk/ms-office-training-manuals.html.