Welcome to the forum. The function you want is a feature of the GS3 camera and it's native to most, if not all android phones.
Open the camera app on your GS3. You should now see a row with 5 icons just above the camera viewing area. Tap the settings button (on the left) and scroll to the bottom of the window that pops up. Make sure the "GPS tag" option is on, and then the info is automatically included in every pictures data.
You can verify it works by taking a picture of something. When the thumbnail shows up in the lower corner tap it for full screen viewing, then press the phones menu button (soft key on left side of home button). Scroll to the bottom of the menu that pops up and third from the bottom you'll see the option "Show on map". Tap it and google maps will open to that exact spot.
A few things to keep in mind.
If you ever turn off your phones GPS, make sure it's on before taking the pictures.
Also the GPS location is recorded for the position of the camera when the picture was taken, NOT the object in the picture.