As a follow-up to my blog post on Qt Books, here are some other great resources for learning Qt. Different people learn in different ways and at different paces. The various training resources I've listed here should accommodate you whether you're looking for an intensive week of formal training or just desire to brush up your knowledge in your spare time.
The official Qt training material used by ICS and other training partners of The Qt Company is available  from a github repository. This includes PowerPoint slides for the training modules, as well as source code for the examples and lab assignments. These are generally kept up-to-date to reflect the latest Qt releases.
The official Qt documentation, which you can access from the Assistant application or on the web , includes many examples and tutorials  that are better suited to learning Qt than the API reference sections of the documentation.
The Qt Company  and ICS  periodically offer live webinars on Qt-related topics. They are also available on demand after the live sessions have been held.
The Qt Company has also put online a number of Qt training videos  on Qt-related topics.
The fastest way to learn Qt is to take a training class from ICS  or another Qt training partner . These classes are in-depth, typically five days long, and include hands-on work on a Qt desktop or embedded board.
And be sure to explore the Qt Resource Center,  which was recently launched by The Qt Company and includes links to videos, whitepapers, and success stories by customers.
Once your Qt knowledge is at a suitable level, I encourage you to consider obtaining Qt certification  to demonstrate your skills to yourself, your colleagues, and employers.