I don't know of any Watcom C/C++ specific books that have actiually been published, so none of the books below directory target Watcom's compiler, but they also have little reliance of other tools where possible (unless otherwise noted).
I've provided links to the author's or publisher's sites where I can, where you may be able to get more information.
The Annotated C++ Reference Manual - the base document for the C++ standards effort. Watcom C/C++ is still mostly an ARM based compiler, but this is slowly changing. (Authors: Margaret A. Ellis and Bjarne Stroustrup, ISBN: 0-201-51459-1, Publisher: Addison Wesley)
The C++ Programming Language (Third Edition) - a complete rewrite of the classic C++ text. (Author: Bjarne Stroustrup, ISBN: 0-201-88954-4, Publisher: Addison Wesley). See also the publishers page.
Working Paper for Draft Proposed Standard for Information Systems - Programming Language C++ - the draft standard available from your local standards organization (also available online here and downloadable here)
Effective C++ - 50 tips to improve your C++. My favourite C++ book. If you don't have this book GET IT! A second edition has just been released. (Author: Scott Meyers, ISBN: 0-201-56364-9 (2nd ed:0-201-92488-9), Publisher: Addison-Wesley)
More Effective C++ - more tips (Author: Scott Meyers, ISBN: 0-201-63371-X , Publisher: Addison-Wesley)
Programming Windows 95 with MFC - a good book for beginning MFC programmers.(Author: Jeff Prosise, Publisher: Microsoft Press, ISBN: 1-55615-902-1)
Revolutionary Guide to MFC 4 Programming with Visual C++ - more advanced use of MFC, with more Visual C++ specific material than above, but still limited. (Author: Mike Blaszczak, ISBN: 1-874416-92-3, Publisher: Wrox Press)
MFC Internals - Inside the Microsoft Foundation
Classes - a detailed look at how MFC does what it does. I found