Jpeg - Tiff - Bmp etc which to use?

[Screwball]

Another post, but there is so much to be learned here, far, far better than any manual!
Yesterday it was recommended to scan photos in Tiff or bmp rather than jpeg - but I did a test scan of a photo, the jpeg size was just 358kb while the bitmap was 5.17 Mb. I compile music supported slideshows of photographic collections (weddings holidays events etc) surely with an average of 80 pics plus music, the rendering will take longer than I have to live, or the computer will melt down?