If this is your first esk8, when programming your VESCs I recommend you start with semi conservative settings
Motor Max: 50a
Motor Min: -50a
Battery Max: 20a
Battery Min: -20a
Your 4.xx VESCs can (REASONABLY, lets not start this fight again 
) handle up to 40a for Battery Max and Battery Min. Any more and you risk either blowing them up, or suffering from thermal throttling until it pretty much kills your experience. As for the Motor Max and Motor Min, thats dependent on your motors. I assume you have dual 6355 which should allow for you to set Motor max and Motor Min up to 70/-70, respectively.
If you are starting from the absolute beginning, watch a few videos like this:
Dont forget that lower/higher amp values for battery max directly correlate with voltage sag / what range you can achieve with the battery.
Additionally if youre using canbus to allow the vescs to talk to each other, that you NEVER unplug the canbus wires while the VESCs are on. If you do your VESCs will go poof. 