here is what I have

the computer has a cd-r/dvd rom drive in the top slot.
I'v got a cd-dvd burner to put in the expansion slot below it.

how do I set up the master / slave. can i leave the top drive that is cd-rw/dvd rom as the master and the dvd burner as the slave or does it have to be reversed?
one more thing, would it be just as easy and as good to set both drives to cable select?