The Dresden RPG site has a great series of articles on the Dresdenverse Laws of Magic, also giving a lot of cool info on how the game mechanics will work.
Overview on the Laws
First Law: Never take a life [with magic]
Second Law: Never transform another
Third Law: Never invade the thoughts of another
Fourth Law: Never enthrall another
Fifth Law: Never reach beyond the borders of life
Sixth Law: Never swim against the currents of time
Seventh Law: Never seek knowledge and power from beyond the Outer Gates