Originally Posted by badmajon
That being said, what is the formula for figuring out how many breakers and at what amperage I can put in there? Can someone guide me to the code?
First, size the breakers according to the load in the house (and wire size). Branch circuits.
Second, you need to do a load calculation to ensure the right size (total amps). I don't have time to get into the nuances of the calc's, much of it based off sections 210 and 220 in the NEC. If you want to study, there is a great book by Charles Miller, "Illustrated Guide to the NEC, based on 2011 NEC." It has the load calc sheet.
There is additional things to do like balancing your panel, etc.