Just follow The Links As its your first map application.
http://mobiforge.com/developing/story/developing-with-google-maps-v2-android Follow the link and check 1)make Sure U have google map v2 support library (Add android-support-v4) and
public class MainActivity extends FragmentActivity {
2)Check and modify the Manifest 3) In layout
4) In Activity
SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
googleMap = fm.getMap();
It will solve your Problem.