Inside SharePoint Integrating Office Applications

Very detailed article about the "inside" of Microsoft Sharpoint 2007, especially about the WebDAV Client Redirector architecture. Even better, there is a code download included to get around some of the shortcomings of the current Sharpoint Client communication possibilities:

Source:
Inside SharePoint Integrating Office Applications

Update on WebDAV Credentials in Vista

Here's another good article about the WebClient Credential issue on Windows Vista with some more details:

Source:  Prompted for Credentials when Accessing Documents in MOSS 2007