It's layered over the top of the image using the text tool in Photoshop Elements. Elements can be pretty cheap if you get an older version. I am using version 6 at home and only version 2 at work. There is a freeware program called GIMP that is worth looking at if you are just starting with image software. It can do everything you would be wanting to do at this point.
I have thoughts of doing a version of the whole thing in an antique map look. I will let you know if I get anywhere with that.