If she/he is new to you I would only feed 1 pinky the first time or two. Once you're sure that your snake is feeding well, (no regurges and digesting quickly) then move up to 2 pinkies per feeding.
I typically feed mine 1-2 pinkies every 5 days. If the pinkie is a bit larger or if I'm moving up a food size then I'll give them time to get adjusted and only feed 1.
If it is a smaller pinky then I'll usually give 2.
(A 'larger' food item is 1.5 times the width of the widest part of the snake, a smaller food item is usually about the width of the snake)
Hope that helps.