onemeg: I did search but cannot find this info: when I visit a place of power and get a buff, I see a symbol showing how long it will last on the main screen at the top, but I cannot seem to find anywhere that says what the buff actually is...or a list of them anywhere, even in the manual. Can anyone help?

Avogadro6: Don't have the game installed anymore, but I think I remember you had to check the character stats. Either way, here's the list:

http://witcher.wikia.com/wiki/Circle_of_Power