if you don't have a scanner, you can usually get a shop like Kinkos or the UPS store to scan them for pennies, you will need a memory stick to transfer it to your computer then upload the files to Roll-20. As long as it is for personal use and you do not distribute copies, other than visually on the desktop, there is no copyright violation. I don't use modules, but there is a vast library of images in the marketplace, you could build almost anything with tiles and art from there and the web. I have built small towns, part of a city, forests, ruins and any number of dungeons from those sources.