Qt for Python (PySide/Shiboken)

Guys, I still don't get how to use slots/signals, specially how to annotate a method on Python. I want to have a method receiving an object/array from Qml and work on this on python. Then, I want to output to Qml either an Object or a Dictionary. So far, I have only one connection that uses QVariant. I could copy and paste, but I would still not have an understanding. On my search at the docs I could not find anything strictly related to these annotations.