how to configer mx record and host ,cname in isp domain?

hi…

i install exchange server2003.but i have faced one prob.mails is not comming well i confifered every one but i don’t exactly create mx record and some other in isp domain.plz tell me what i have configer in domin.my public ip :210.255.231.255

system ip :192.168.1.30

and isp domain ip 66.76.32.14(andhra.com)

this is base…