[Koha] Cataloging books which doesn't have ISBN etc.,

Hi, I am trying to catalog the books which doesn't have any ISBN etc., for me to import. I was using Marcedit and sometimes directly from Koha to add books. However, I was not able to make out how to store the cover image of the book. I want to scan the book myself and store it so that when the book is searched, it shows the image as well along with the other details of the book entered. Can you please help me out? Koha version: 3.02.3 Thanks & Regards, Somasekhar Rao K