Find GPS Coordinates
The first thing to know is what format your equipment uses. For instance, my in-dash mapping equipment will not use decimal (DD) format. So I have to make sure I obtain (DMS) degrees, minutes, seconds format coordinates. Here are some examples of each:
Decimal degrees (DD): 37.759583, -80.905889
Degrees, minutes, and seconds (DMS): 37°45'34.5"N 80°54'21.2"W
Once you know, it is a very simple process to obtain the coordinates you need. Simply go to Google Maps (https://www.google.com/maps/) and input your desired address. Right click on the location in the map and copy the DD coordinates. If you need the DMS coordinates, copy and paste the DD coordinates into the maps search box and hit "enter". Below you will find that Google has given both formats for the same location. Now just copy which ever or both to input into your device and you are on your way.
There are other mapping services besides Google, but the basic process will be the same in most cases.