Windows API (Win32 API)

Tutorials
theForger’s Win32 API Tutorial
FoosYerDoos
Sunlight
FunctionX
Stromcode
Reliable Software
Catch22 Productions
from the ground up
Fallout Software
Nomad Programming
A few Win32 articles
Code Project
Pelles C Source Code
Wikibooks Windows Programming
alexfedotov.com
Bob Moore’s Win32 Tip Site
Joseph M. Newcomer MVP Tips
mvps.org
Al’s Win32 Programming Tutorials

Reference
MSDN Windows API Reference
Resource Files Documentation
Win32 Help Files
Using the Windows Headers

Tools
ResEd (resource editor)
Code::Blocks (C/C++ Compiler/IDE)
Dev-C++ (C/C++ Compiler/IDE)
lcc-win32 (C compiler suite that comes with a resource editor in the file weditres.exe)
Pelles C (C compiler suite that comes with an integrated resouce editor)
Winspector (Windows Message Spy)

Blogs
The Old New Thing
XN Resource Editor