The program will automatically detect any maps you have stored on your system and you simply click on the one you want to see. Once it is loaded, you can move around the map with the arrow keys, or simply by using the mouse.
The best feature is being able to light up a certain material on your map. That is, you can blackout everything on the map apart from your chosen material so you will know exactly where to dig out next time.
Terrafirma is an application that will make Terraria players happy for a long time to come. Not only is it easy to use, but it will help you with prospecting your new world.