Click, "More Settings"
Under "Placemark Placement," enter latitude and longitude
You can use the following:
Decimal Degrees (DDD): Set in the "degree" coordinate.
Example: 49.11675953666N
Degrees, Minutes, and Seconds (DMS): Decimal precision is set in the "seconds" coordinate.
Example: 49 7'20.06"N
Degrees, Minutes with Decimal Seconds (DMM): Decimal precision is set in the "minutes" coordinate. Example: 49 7.0055722"N. (Here, 20.06 seconds above is divided by 3600 to get the decimal minute value for 20.06 seconds.)
Separate coordinates with a space:
DMS example: 37 24 23.3
DMM example: 49 7.0055722
Use a single quote for minutes and a double quote for seconds:
Example: 49 7'20.06"
Direction notation (North/South, East/West):
Use N, S, E, or W to indicate direction.
Example: N 37 24 23.3 or 37 24 23.3 N
Use the minus sign (-) for western or southern positions: When you use this, do not specify a letter.
Example: 37 25 19.07, -122 05 08.40
Note: Don’t use a plus sign (+) for northerly/easterly directions.
Latitude first, longitude second: Unless you use a direction notation (N, S, E, or W), enter latitude before longitude.
Example: 122 05 08.40 W 37 25 19.07 N or 37 25 19.07, 122 05 08.40
Separate pairs with a space, a comma, or slash:
37.7 N 122.2 W
37.7 N,122.2 W
37.7 N/122.2 W
Information above taken from "Google Earth Help"