Here's my copy of the Munson plan:
-When they're on single pinks (2-3g), I feed every 4-5 days. (Snake = 4-15g)
-Double pinks (3g x 2) every 4-5 days. (Snake = 16-23g)
-Small fuzzies (5-7g) every 5-6 days. (Snake = 24-30g)
-Regular fuzzies (7-9g) every 5-6 days (Snake = 30-50g)
-Hoppers (9-12g) every 5-6 days (Snake = 51-90g)
-Weaned (14-20g) every 7 days (Snake = 91-170g)
-Adult (24-30g) every 7-x days (Snake = 170+)
-Jumbo Adults (40-50g) every 7-x days (Snake = 400g+)
Note: Adult females are fed more frequently than adult males (especially following brumation). Females are fed every 6-8 days; males are fed every 7-14 days.
This is by no means scientific.
One bit of advice is to get a scale that weighs in grams. Weigh your snake and the prey (mouse) before each feeding and keep records.
I only feed frozen thawed. Almost all corn snakes will eat frozen thawed. The only reason to feed live, in my opinion, is when for whatever reason it is the only way the snake will eat.
When I got Cleo she was 6 weeks old and 14 grams. She ate a 2 to 3 gram pinkie mouse every 5 days. That's a normal feeding schedule at that age. I have records of every feeding and weight from that day to this.
I agree with checking out the Munson plan, though I always feed the longer interval and lower prey weights. That is until I get to the point where I don't need the chart any more.
For example, Cleo is going on 2 years old now weighs 258 and gets a 13 gram mouse every 10 days.(size will increase gradually as I select from the big bag of frozen small adult mice) She has a nice steady growth rate that puts her on a good track to full adult size in another couple of years but it is way less than Munson as you can see. If she needed the mouse size Munson gives for healthy growth I'd do it but she doesn't as evidenced by her weight at 2 years old.
One more thing. almost no one feeds Jumbo mice. I have an adult corn snake too, and she gets 20 to 25 grams every 10 days. She weighs 550 grams.
Munson is a guide but you've gotta use common sense and learn your snake and its growing habits. By the time you aren't as reliant on Munson you will have the confidence and experience to depart from it like I did.