Google's Microsoft-specific search.
MSDN - Microsoft Developer Network.
Visual Studio 2008 - Learning Portal.
ASP.NET - Web development, Microsoft style.
Windows Live Admin Center - Windows Live for domains.
Office Live - Document sharing, web sites.
Windows Sysinternals - Windows system utilities.
Blogs & Podcasts
Scott Hanselman does a weekly podcast (Hanselminutes) often, but not always, related to developing software on Microsoft platforms. Scott also posts a page listing his favorite software tools which, seems to me, ought to be called Hanseltools.
Beth Massi looks at the Visual Basic side of .NET development.
Rocky Lhotka is an advocate of object oriented design and creator of the CSLA .NET (Component-based, Scalable Logical Architecture) framework for business object development. I hope to try out the CSLA framework soon as I get past a couple other learning-curve projects.
The "fighter pilot" and "that indigo girl" share their expertise on data binding and WCF, among other things, and are principals at iDesign. The iDesign website has documents describing their coding standards available for download.