There are changes to the Visual Studio 2010 help system that you'll want to learn about.
For example, the new 'Manage Help Settings' menu item:

The menu item opens the new 'Help Library Manager' dialog:

From MSDN: "The Help Library Manager (HLM) application allows you to manage product documentation in the local Microsoft Help 3.0 content store. Using HLM, you can find and install new content from the web or from media, go online to get updates for your offline content, and remove offline content. The Help Library Manager also manages settings that allow you to customize your help experience."
Read more at: Help Library Manager