The entire content of the first edition of
Mark Summerfield's book
GUI Programming With QT4 is now available
for download.
Alternatively, if you'd prefer the second edition, in hardcopy, you can buy it here:
The book starts from the absolute basics, assuming that the programmer knows nothing about QT, moves onto the various windows and dialogs available, before moving on to creating your own widgets. The second part of the book looks at container classes, I/O, networking and XML, before moving onto advanced concepts such as internationalisation, plugins and multithreading in the final section.