drag & drop

Patricia....
I think you'll like Keynote. You simply drag the sound files onto the page where you want them to run. Then you place them in the order in which you want then to play by simply dragging and dropping. Then you save and go to sleep. Haha, not quite that simple. I to had file size issues, but mine were due to using too many sound files. Let's just say I had an orchestra of animals and about 20 sound files. I had to cut my project back significantly, but the point is, creating it, then making adjustments to it, was VERY simple. Hard to explain here, but do try it.
Keynote is not part of iWorks, so I doubt your Board has it. It comes with Apples new word processor called Pages. But iWorks has a lot of cool programs and I would definitely experiment there.