MFC related sites:

www.codeguru.com

Codeguru - The number one developer site!

www.codeproject.com

The Code Project - Free source code and tutorials.

PJ Naughter's Home Page

Lots of MFC source code.

BCGControlBar

MFC extension library to create the advanced user interfaces.

Visual C++ Ideas

Notes on MFC based solutions to simple and more complex problems.

Softech Software

Visual C++ source codes for Windows 2000/NT/XP/9x/ME/CE.

UCanCode Software

Software components with full source code (XD++ MFC Class Library).

Misc. Programming sites:

Sysinternals

Utilities and source code related to Win9x/NT/XP internals.

SourceForge.net

Very useful site with lots of open source projects.

Links to Links:

programmeer.pagina.nl

Collection of very useful links.