Stupid Question

Ok i know this is a newbie question... when making Icons is it better to get screen caps of the shows or pictures of the actors/actresses? I'm attempting to do some BtVS/Angel Icons for my RPG site. Anyways which is better? And if it's screen caps could someone point in the direction of a good site? Thank you for your time, this is a question that i have been wondering about. [[also i am sorry if this wasn't suppose to be posted here, as i have said before, i am very new to all of this.]]