The Digital Story: "The Holiday Photographer" - Podcast #12
One drawback to bouncing light is that the subject's eyes can go dark because the illumination is from above. A great trick to fix that is to attach a plain white business card to the flash head with a rubber band as shown in this illustration. It "kicks" just enough light toward the eyes to brighten them up while still getting the benefits of bounce flash.
Generally speaking, I increase the ISO to 400 for bouncing because you do lose some light from the added distance and the surface of the ceiling. Otherwise, you should be able to use Program mode and auto flash.