Great QT book

Could anyone suggest me which is a great QT book to begin with?

Thanks

C++ GUI Programming with Qt 4
By Jasmin Blanchette, Mark Summerfield ................a good book and with qt assistant ..
foundations of Qt development
by johan thelin .... also a nice book ...

the docs mention a free online book on this page: http://doc.qt.nokia.com/4.6/how-to-learn-qt.html

it is for Qt 4.1, but that might not be relevant in the beginning