This is the faction list that is often used, can't confirm the ranges myself. 1 points represents 1 normal kill. Depending on faction you are working on you MAY get more points from 1 kill. (e.g. raid mobs and such).
Ally = 1450 to 2500
Warmly = 1100 to 1450
Kindly = 750 to 1100
Amiable = 150 to 750
Indifferent = 0 to 150
Apprehensive = 0 to -150
Dubious = -150 to -750
Threateningly = -750 to -1100
Ready to Attack = -1100 to -2500