FAQs, Tips, etc
Bob Moore's MVP site
A collection of very helpful tips from a real guru.
MVP tips by Joseph M. Newcomer
A collection of articles dealing with topics most MFC programmers should know about.
Visual C++ FAQ (German)
The FAQ of the newsgroup microsoft.public.de.vc.
A very handy and easy to use (and install!) image library. Completely free but very valuable.
Paul DiLascia's CTrayIcon class
This link points to an article by Paul DiLascia, providing a class that makes it very easy to get an icon in the system tray.
One of the most awful flaws in the windows user interface is the inability to resize most dialogs. Some dialogs simply must be resizable. Implement your own resizeable dialogs by inheriting them from this nice class.
CListCtrlEx and CListViewEx
Two classes that let you do much more, much more comfortable than their MFC parents.