C# Language Specification
The C# Language Specification is the definitive source for C# syntax and usage. This spec contains detailed information about all aspects of the language, including many points that the documentation for Visual C# doesn't cover.
You can download this spec from the Microsoft Developer Network (MSDN). If you've installed Visual Studio 2012, you can also find the spec on your computer in the Program Files (x86)/Microsoft Visual Studio 11.0/VC#/Specifications/1033 folder. However, installations of Visual Studio Express 2012 don't include this file.