caster/camber settings

i come from a long line of dirt track drivers and have the oppertunity to become a third generation driver this year i dont know much about driving or setting up a car for that matter but im learning from family and friends that have driven or crewed over the years now im trying to absorb as much info as i possibly can at my ripe old age of 33 and most well almost all of the work is being done by my father and myself i want to do more than just drive i want to know my car inside and out but there are things im trying to understand but most just goes rite over my head like for example ....roll center i found several diagrams on how to take the appropriate mesurments ... and calculate what the roll center of my chassis is but what exactly is roll center and whats its purpose? next question ... im gonna use stock ride hight my car is a mid 70,s GM  metric chassis but i do not know what to set my castor/camber at as i mentioned the track is a 5/8 high banked clay oval and my spring rates are lf..900   rf..1100 lr..225 rr 175.. and using pro ss series shocks all around if anyone can give me some sort of base set up the knowledge will be much appretiated and will be used wisely