Personally, I have them on weaned rats (30g to 45g avg) once a week at that size.
Part of your decision on a feed schedule and what to feed is how interested you are in having them add weight, part of it is convenience (ie, not everyone can easily do 5 days, but a lot of people can easily feed once a week on weekends), part of it is what your snake wants (some eat less often than others, some like smaller prey).
Find something relatively convenient for you, and start from there. Pay attention to how your snake responds and make adjustments as needed.