Hi, Thanks. I know how you feel, I was worried but his forum is a great place to come for help though so you're in the right place. Its good to speak to others in similar situations.
They say they take jps and pngs too just that they ask for PDFs as the main suggestion, i don't think its a restriction just preferred if possible.
A PDF is a file format developed by adobe for presenting documents (Portable Document Format), it can contains text and images. You can use it to bundle bunches of scan together. We made all our scans as jpgs and used software to put them together. There are various ways of putting pdfs together, some modern scanners allow you to output pdf. I would look into it but remember just jpgs or pngs are excepted but you may end up uploading a quite lot of individual files.
For the scan setting it varies scanner to scanner but you would be looking to use the software provided with your scanner, it will most likely contain some advance settings that will allow you to change dpi (dots per inch) and colour settings, each scanner and computer setup can be quite different so its had to say.
I think if you can use the scanning service and you're not familiar with image file formats it might be a better help, I hope and am sure other here can give you advice on this as we didn't use the scanning service personally.
Hope this helps a little, good luck