With photographic material I get all sorts of archives from a few slides or printed photographs to many hundreds or thousands of images. Most customers want their images back as digital files. Either as .jpg or .bmp images.
The key thing to remember, particularly for large archives is that I would like you to be able to quickly find the physical picture or slide that matches the digital image. To do this I take a lot of time creating folders that match how your archive is presented.
You might have a round slide carousel, or a small Kodak yellow cardboard box or the printed photos might be in a snappy snaps envelope or giant padded red velvet sticky album. Whatever format you have your images in I will create named folders so you can find what you are looking for. If you have something like 600 images they are going to be across many different envelopes, boxes or albums and I will name each one. So you will find folders like “Kodak B Durham 1976” or “Large white Envelope B” on your hard drive or USB stick.