I tend to create my own maps and dungeons in Photoshop, however, as somebody who is not a professional digital artist this is something that takes me a lot of effort and only looks half-decent. However, I am sure it is as I wanted it. There are plenty of resources where materials are available. In essence, there is at least these options: make something on your own, buy stock images and maps, get images and maps for free or employ a freelancer to do it for you. In the end, everything happens outside of roll20 as there are much more sophisticated and easier ways to get your resources. You can then upload the stuff to your library and use it in your campaign. Wanna build something yourself? Check out these textures: <a href="http://cgtextures.com/" rel="nofollow">http://cgtextures.com/</a> Looking for maps and people who know their stuff? <a href="http://www.cartographersguild.com/content.php" rel="nofollow">http://www.cartographersguild.com/content.php</a> And then of course there is plenty more things on websites such as deviantart.com and more. Take a look around and make sure to give credit / pay for using the stuff. Also useful: <a href="http://pyromancers.com/dungeon-painter-online/" rel="nofollow">http://pyromancers.com/dungeon-painter-online/</a> - an online tool for creating maps. It also has some stock textures and buildings etc.