Indoor school reunion job

[Andrew Sutcliffe]

I have been hired to shoot a school reunion and have just been asked to do some outdoor full group shots and some candid shots of the guests indoor during the actual event. For the outdoor full group picture, there will be about 40 guests stood Infront of the school, which I am planning on using natural light for, is this right? And for the indoor ones, I am planning on just using a camera mounted flashgun and bounce it off the ceiling with the bounce card up? Please could anyone suggest any better ways of doing this?

Thanks again,
Andrew.