- Qt Project is for sure the starting point
But Qt is based on C++, and I was out of knowledge of it. In internet it is well known the work of Jasmin Blanchette and Mark Summerfield: C++ GUI programming with Qt4. I found a pdf of it’s first edition. Here I found that also the second edition is available. The book is great for learning Qt, but I primarly used it for learning C++ 
it has a great appendix about C++ very compact but effective. It will give you the required C++ basis to use Qt in a proper way!
A great resource is also this page: it refers to a list of official tutorial and example included in the Qt Documentation. Out of these example I made some of the QtCreator section and the QtQuick section as I wanted to create the UI of my program with QML.
Except tutorial there is another great place to visit: Qt eLearning videos. I have watched some of those and would like to suggest a series about QtQuick recorded ad Qt DevDays 2010:
- QtQuick – part 1 – Introduction to QtQuick
- QtQuick – part 2 - User interaction / Input and States
- QtQuick – part 3 – Animation and visual effects
- QtQuick – part 4 – Arranging items / Debugging QML
I have also watched a video about deploying to Symbian devices, and another for Android development.
This is a short selection of the useful documentation you can find online. I will complete this post with new resources that I do consider important, but if you have something to suggest, don’t hesitate!
