There is a web-version available of the AutoCAD Map 3D 2011 User Manual online on the Autodesk website. Not only a usefull referencebook online, but also requests to Google will find their answers in this documentation.
In addition to the User’s Guide and Reference Guide, users also get web access to the Getting Started Guide, Tutorials, Workflow Guide, and GIS Skills for Engineers online, incl. all animations.
Also the AutoCAD manual and AutoCAD .NET Developers Guide are online on the Autodesk website.