In a previous post I noted that some WinAPIs can be found on the web by searching for the string NativeMethods, which seems to be a Microsoft standard naming convention.
Today I came across pinvoke.net, a website dedicated to the documentation of WinAPI calls from .Net.
There is even a plugin for Visual Studio (2003 and 2005) that integrates pinvoke’s wiki contents into the IDE.

[...] Managed Windows API library for .Net I mentioned accessing native Win32 APIs by .Net some time ago. [...]
[...] For other APIs, see my previous posts. [...]