Whilst browsing the site I've noticed a pretty heavy leaning towards Photoshop as the map-maker of choice. Now, I'll point out here that my knowledge of either program is limited to an introductory short course... that I failed, so I'll probably need it explained with diagrams, pictures and a lollipop reward at the end, but to my understanding, Illustrator seems like the obvious choice for map-making ahead of Photoshop. I could see doing some fine-tuning with filters once a map is made, but the vector paradigm seems to lend itself naturally towards map-making whereas Photoshop seems more about making pictures prettier rather than making anything from scratch.