Hi there Mercutio361, I came here for exactly the same purpose a couple of years ago, as have many, many others. So welcome to the Guild! There are tons of tutorials available here to help you achieve your goal. Spend some time browsing the tutorials section and pay attention to what kind of software is required for each style of map. You'll find that Photoshop and GIMP are the two most prominent forms of software used (with CC3 coming a distant third).

Cheers,
-Arsheesh