Microsoft

http://www.microsoft.com/net/

http://www.microsoft.com/italy/net/

Msdn .NET development

Ecma

http://www.ecma.ch/

Ecma: C# Language specification

C# / .NET Resources WebSite

http://www.csharphelp.com/

http://www.c-sharpcorner.com/

http://www.gotdotnet.com/

http://www.oreillynet.com/topics/dotnet/

http://www.codeproject.com/

http://www.csharp-station.com/

http://www.dotnetbuzz.com

http://www.csharptoday.com/

http://www.devasp.net/Net/

http://www.codeguru.com/

http://www.csharpindex.com/

http://www.managedworld.com/

http://www.learn-c-sharp.com/

Hyperlinked C# Grammar