Here’s an excellent collection of Office 2010 documentation from Microsoft containing overview, product guide, getting started, and new features of various Office 2010 products.
These documents are available in PDF, XPS, or DOCX formats.
Download the documents individually or the entire pack. The entire pack PDF format size – 39.4 MB
The pack contains documents related to -
Access 2010, Excel 2010, InfoPath 2010, Office 2010 Suite, Office Mobile 2010, Office Web Apps, OneNote 2010, Outlook 2010, PowerPoint 2010, Publisher 2010, SharePoint WorkSpace 2010, Word 2010
You can download it from here- Office 2010 User Resources