Adam,
First disable momentarily any security on the Access Point/Router just to test the connectivity. The on the computer try first as root:
iwconfig wlan0 mode Managed echo $? #the reply should be 0 once this is done, try
iwconfig wlan0 essid MY_Access_Point_SSID echo $? #again this should be 0 && that means that It associated you to your AP or router
#Once you get associated & able to browse the net. You can reenable security on your router/Access Point & trying to reconnect using Network Manager