Pacifier: do or don't?

I have heard good and bad about them, but I want to know what you think? I do feed, and she's doing very well with that, but she isn't even a week old yet- should I wait a while, or should I not do it at all? The only reason I am considering it is because she seems to be very calmed when sucking on her hand, or my finger. Did/do you use one?