i need to file two different state but i have no idea how

first i am big idiot with this, i need help
I was in Mississippi as a AIT and now i am stationed in New Mexico state. Do i add up pays that i got in Mississippi time period and put it on MS state income and New Mexico as well in there?
Also if above is right, which pay do i add total? is it adding up all the net amount pay (i have no idea which one to add this too)??
thank you for help