Take a look at qt.nokia.com and forum.nokia.com. They have some eLearning stuff, tutorials and demo applications there.
qtcreator (from qt.nokia.com) also comes with lots of demo applications.
Last but not least, the PDF for the book C++ Programming with Qt 4.1 is available at qt.nokia.com for free. It doesn't cover Qt 4.6, but will get you started with Qt very well. It's a great book IMHO.