Have you had a look at the awesome Qt documentation? 🙂
http://qt-project.org/doc/qt-4.8/how-to-learn-qt.html
This page gives you some pointers on how to get started.
You’ll definitely want to bookmark http://qt-project.org/doc/qt-5/index.html
In my opinion there’s no right end to start from – where you should start depends on what you want to do with Qt. But if you’re going to create GUIs then GUI creation and programming is a good start.. I’d advice you to have a look at the Qt demo app, explore the parts of Qt and then do a few tutorials.
Usually I learn by implementing something. Have an idea of what I want to do, then implement it whilst reading documentation.