android google map in my app

After reading your question, I just went to Google and in less than 10 seconds I found this: link . Reads carefully that says everything there.

EDIT:

To be more precise and do not go "lost" the search I leave here the following code snippet available on the page that I suggested.

import com.google.android.gms.maps.*;
import com.google.android.gms.maps.model.*;
import android.app.Activity;
import android.os.Bundle;

public class MapPane extends Activity implements OnMapReadyCallback {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.map_activity);

        MapFragment mapFragment = (MapFragment) getFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap map) {
        LatLng sydney = new LatLng(-33.867, 151.206); /* AQUI A ALTITUDE E LONGITUDE */

        map.setMyLocationEnabled(true);
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(sydney, 13));

        map.addMarker(new MarkerOptions()
                .title("Sydney") /* TITULO DA CIDADE */
                .snippet("The most populous city in Australia.") /* LABEL OU SEJA, UMA PEQUENA DESCRIÇÃO */
                .position(sydney));
    }
}

Regards, thecreator

A quick way for you to start is to create a Google Maps Activity

Italreadygeneratesan.xmlforyoutoenterthemapskeyandalreadygivesyoualinkonhowtogeneratethiskey.

More information on Getting Started in Google Maps V2: link