Casting Time for Rune spells is the time it takes to draw the rune. Activating the rune is a swift action (or a free action if activated immediately after being drawn). Rune spells last 1 hour after being drawn.
Target for Rune spells is the area of the rune being drawn. For example, if the target of the rune is "adjacent square", you draw the rune in an adjacent square. "Self" runes are drawn on yourself. And so on. Runes which take up multi-square areas (such as a 2x2 area) do not take extra time because of their size.