GeoAxes will plot a network of latitude and longitude lines.
The Geographical Axes
Tip
If you are not exactly sure what numbers to put in, you may try Tools > Geographical Management and select the correct datum/coordinate system, then press the button Default display and then Update detailed and you may get an idea of what number to enter into the Geographical axes settings panel.
Set the Min and Max Longitude and Latitude, and set an appropriate increment for each of them. The image below shows and example of a graticule with and increment of 2 degrees over an area.
Example of GeoAxes