Working with StyleSheets

When reading help files any things, nothing really tells you what properties can be used within the StyleSheet.

When setting like:

color:
background-color:
border-size:
border-radius:

And the different states:

normal
hover
focus
pressed

Is there any good documentation for what can be set with each kind of Widget?

StyleSheet Examples
StyleSheet Reference

I don't use stylesheet in Qt, but I used to in XHTML.
I though the keywords were the one from CSS, which you could find at http://www.w3schools.com/CSS/CSS_reference.asp

Thank you both for all your help