Microsoft Dot Net resources
Microsoft.Net Home Page
Go Dot Net (Microsoft)
ASP.NET (Microsoft)

Non Microsoft Resources
Chris Sells website
Dot Net Junkies
Dev City
Dot Net 247
Code Project
CSharp.org
Dot Net Extreme
Dot Net 101
Dot Net at Oreilly
CodeNotes
World Of Dot Net
Devx Dot Net
DevHood

ASP
4 Guys From Rolla
aspnetpro.com
aspalliance.com
123aspx.com

Porting efforts
Mono Project
dotGNU
Shared Source CLI (codename Rotor)
Article about .NET Porting efforts
.NET on Java

.NET Tools and Utilities
SharpDevelop - Open-Source IDE for C# and VB
Anakrino - IL to source code
Reflector - ILDASM with MSDN Help (and more)

Miscellaneous
.NET News