I decided to learn Python Gui development and, as PyQt is non-free, the choice was PySide for it. But, unlike PyQt, PySide doesn't have any tutorials or screencasts, just documentation useless for very beginners. I have no Qt experience, so even setting up development environment in Ubuntu is a problem. Could you advice something to learn from?
If you are going to just learn GUI development with Python, does PyQt not being free really matter?
And make sure you actually know the PyQt license before arriving at such a conclusion!
I am not surprised that you couldn't find any tutorials at the time PySide was trying to get its first stable release ever. =) Now that PySide 1.0.0 is released, API is stable and bugs are ruled out, you can find newbie and advanced PySide tutorials with the rest of documentation and links to other resources at Qt Wiki.