If an Android device has GPS , how can it be activated and used?
First of all, you need to make sure the GPS is active. To do so:
1. Open your settings menu
2. Go to "Location & security" and enable "Use GPS Satellites".
Then you will need some software to use the gps capabilities. You can either go with the Google Maps app, which has a navigation feature embedded or, if you don't want to be dependant of internet connection, you could get a specialized GPS application (such as the ones you find on dedicated driving GPS devices). There are a few of them available in the market, but i would recommend iGO or NDrive, as they are used in various high-end dedicated devices. Or maybe your device already comes bundled with such an app (as motorola devices with its MotoNav).