Have you ever looked at the Spiderinnet?
Neither had I, until now, but the intro sounds really promising, and the list of articles is very impressive:
This blog focuses on Revit Addin Wizards, Coders, and API Widgets. Coding languages exercised in the various Wizards/Coders/Widgets include but are not limited to C#, VB.NET and C++/Managed C++/CLI. Different Revit versions, flavors (Revit Architecture, Revit Structure and Revit MEP) and bitnesses (x86 or x64), different Visual Studio versions such as 2008 and 2010 and editions such as full fledged and Express will also be addressed when necessary.
The articles cover topics such as:
Very impressive indeed.
I look forward to hearing what you think of it!