Life Time printed a set of basic photo books in the early 70's to early 80's one text was just for caring and restoring old photos. Kodak also published a very good book on caring for old photos. I would check the web and find a good text with step by step directions. I would also scan the prints to disk (if the prints are not so large as not fit on flatbed scanner) I would check to see if your grandfather's negatives are still around.