1) Firstly you can use the Qt Assistant Manual
http://doc.qt.nokia.com/4.7-snapshot/assistant-manual.html
2) You can also read the book "By Jasmin Blanchette, Mark Summerfield - C++ GUI Programming with Qt 4." .
The Only Official Best-Practice Guide to Qt 4.1 Programming "Using Trolltech's Qt you can build industrial-strength C++ applications that run natively on Windows, Linux/Unix, Mac OS X, and embedded Linux--without making source code changes. With this book Trolltech insiders have written a start-to-finish guide to getting great results with the most powerful version of Qt ever created: Qt 4.1.<p>Using "C++ GUI Programming with Qt 4" you'll discover the most effective Qt 4 programming patterns and techniques as you master key technologies ranging from Qt's model/view architecture to Qt's powerful new 2D paint engine. The authors provide readers with unparalleled insight into Qt's event model and layout system. Then, using realistic examples, they introduce superior techniques for everything from basic GUI development to advanced database and XML integration.Includes new chapters on Qt 4's model/view
http://books.google.co.il/books/about/C++_GUI_Programming_With_Qt_4.html?id=tSCR_4LH2KsC&redir_esc=y
3) Finally you can read and appreciate my article :
Two Ways to Realise the Composite Pattern in C++ and Qt
I will be glad if it helps you :)
Good luck.
Regards,
Alex.