Overworld commands:
worldtravel: This is used to enter and exit the overworld NOTE: You must be standing in either the overworld map or an exitroom (Help EXITROOMS) for this command to work.
travel <dir> <distance>: This is used to move on the overworld map where direction is n, s, e, w and distance is 1 to 10 (default is 1)

Existing area locations: (will be updated as areas are added)
Cairhien: 41,18
White Tower: 39, 14 (partially complete)
Cold Rocks Hold: 59, 16
Bitter Water Sept: 58,17
Black Cliffs Hold: 59, 14
Far Madding: 37, 27
Bandit Camp: 44, 18
Amador: 21, 29
Maerone: 39, 21
Naridal: 29, 8
Salidar: 27, 30
Four Kings: 34, 21
Damodred Manor: 42, 19
Whitebridge: 29, 21
Stedding Shang'tai: 51, 30
Malkier: 39, 5
Aridhol: 26, 19
Illian: 33, 34
New Braem: 36, 19
Tarwin's Gap (Construction Site): 44, 5

There are also terrain areas of all types.
Also, cities that are not yet built will not allow exiting the map.

Map Terrain Types:
(exiting a square that is not linked to a major area will drop a character into a terrain area of that terrain type)
*: Blight
$: Shallow Water/River/Lake
:: Deep Water/Ocean (impassable currently)
@: Forest
~: Hills
#: Desert/Aiel Waste
/: Grasslands
^: Mountains (impassable currently)
+: Cities (only currently built cities are accessible, see above list)

To reach a destination, enter the overworld map and move to the coordinates of the area you want to reach, and then type worldtravel again.