Full text of valuable book "An Introduction to Design Patterns in C++ with Qt 4" by Alan and Paul Ezust (Suffolk University) is now available online at http://cartan.cas.suffolk.edu/oopdocbook/opensource/ under OPL license.
The authors also provided slides suitable for courses and exercises.
C++ taught "the Qt Way"!
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Another free Qt 4 book
And from Mark Summerfield's web page you can also download another free Qt 4 book under OPL license: C++ GUI Programming with Qt 4 (1st edition)