First, I assume that you have downloaded the latest "NodeXL Source Code" release from the CodePlex Downloads tab at
http://nodexl.codeplex.com/releases. The CodePlex Source Code tab is no longer used.
Here is where you can find the documentation:
1. The download tab has instructions for building the source code in both Visual Studio 2008 and 2010.
2. The source code contains a "ReadMe.txt" file that lists and explains all the Visual Studio projects in the solution.
3. It also contains a NodeXLApi.chm file that documents the important NodeXL classes in a traditional help file format.
4. The source code files themselves are extensively commented.
I want to point out that you do not need the NodeXL source code if all you want to do is incorporate a NodeXL graph in your own application. You can do that with the latest NodeXL Class Libraries download on the Downloads tab, which contains prebuilt
.NET assemblies that contain, among many other things, a graph control (called NodeXLControl) that you can drop into your WPF or Windows Forms application. The source code is only for advanced programmers who want to customize NodeXL in a way that
the Class Libraries won't allow.