best source to learn QT

Question

what are some good sources to learn the QT framework for free

Answer 1

QT wiki maybe, or YouTube, i've seen some playlists with tons of videos each, i'm sure these videos will be helpful.

Answer 2

I used the book/pdf "GUI Programming with Qt 4".
It's a little outdated but good enough to get familiar with Qt.

Answer 3

https://m.youtube.com/results?search_query=qt4+tutorial