Do you mean a mirror? or are you just wanting to add a second drive for more space? A mirror would be a RAID 1 setup and you would need 2 drives with the same capacity and a raid controller. Your motherboard may already support this.
As long as the drive controller is already enabled in the bios, all you need to do is attach the drive to the motherbard with SATA and power cables. If it's a new drive that hasn't been used before, you will need to go into disk management and initialze (partition & format) the drive before it becomes viewable in windows.