How do you find the latitude and longitude of a city?
The fastest way would be to use Google Earth.
Just type in the name of the city and it'll zoom into it (make sure you have the right city -- I know there is a Paris in Ontario, but Google Earth will probably zoom into the other Paris). At the border of the frame you will see latitude and longitude.
Or you can go the old-fashioned way and read the lines on a map.
Ordinance Survey (or your equivalent) produces maps, that not only have a kilometer or mile grid, but also give latitude and longitude on the borders of the map.