Decimal degrees but don't include the + for non-neg numbers.
If the radio was located at +34.1991° by -91.83009° you would enter it as:
34.1991
-91.83009
If your radio has GPS then it will auto populate that field in CnMaestro and if you enter the cords in your non-GPS radios they will also auto populate that field in CN Miestro.