Boxa786 is right, there is NO Master or Slave for SATA. Some SATA drives actually have jumpers on them, but do NOT change them unless you know what they are for!
If all you want to do is mount a SATA drive containing both an OS and data as a second drive in a machine that already has an OS in its first drive, just go ahead. The second drive will just be treated as a data storage device UNLESS you specifically go into the BIOS Setup screens and tell it to try to boot from the new second drive.