Of course, you can't really get anywhere unless you understand the map. The map will be used for so many things, but the most useful aspect is to view plot helpers.
Unless the option is turned off on the Options menu, plot helper arrows display on the map at various key quest points, especially where you have to go for the next leg of your journey.
On the map, a yellow dot represents a party member, and a yellow dot with a circle around it represents the PC.
A blue dot signifies an ally, and a red dot equals an enemy. Plot givers show up as white exclamation points, and key locations display as white Xs.
A vendor or store looks like a house, and map exit points appear as white-rimmed black circles.