For now, I can only answer your follow-up question on WTL documentation. WTL is not a Microsoft product anymore. This is open-source. Please see:
http://en.wikipedia.org/wiki/WTL[
^],
http://sourceforge.net/projects/wtl/[
^],
http://wtl.sourceforge.net/[
^].
As to you main question, right now, it is very inconsistent and ambiguous. What is "usage of a class like MFC"? MFC is not a class. MSDN is not really a tool, and so on. If you need an advice on "searching the using of a class", you need to answer my questions I asked you in my comments.
—SA