i bought a computer a few weeks ago and it has a dvd burner. i really know nothing about burners so i have a couple questions. i have a 16X dvd rom drive and a 8X dvd+r/rw cdrw combo drive. what kind of discs should i use? i know there are dvd-r dvd+r and rw discs but i am not sure which to purchase. thans, sean.