Welcome to the Guild Rockwolf66! I recently did a Palladium map for a buddy of mine (killervp) over at the Obsidian Portal, not by chance the same one you are referring to is it? Anyway, you have come to the right place to learn the craft. There are some great tutorials here to help you get your feet wet. If you don't yet have any mapping software, or own Photoshop (the most popular form of software used here at the Guild), my I recommend downloading the GIMP. It is the finest freeware raster graphics program available, and while not as versatile as PS, still is plenty powerful.

Cheers,
-Arsheesh