When I started to develop in Qt (I pronounce QT, I'm French Canadian) I bought the book C++ GUI Programming with Qt 4 (second edition) by Jasmin Blanchette and Mark Summerfield.
Most of what you will find in the book is well covered in the Qt tutorials but I do like to read books (and spent some time away of my computer if I can).
Another good resource is ICSNetwork for Qt screencasts: http://www.ics.com/learning/icsnetwork/
And, finally, a good place to meet other Qt Developers is at Qt Centre Forum. You will find there a Forum, a Wiki, Documentation, Links, News and more about Qt.
