Maps Android V2: java.lang.noclassdeffounderror: c

As many I get the following error: java.lang.noclassdeffounderror: com.google.android.gms.R$styleable when trying to implement Maps for Android V2.

Somehow I must be missing what I exactly am doing wrong, since it's not working. What I tried first is to copy the google-play-services.lib into the lib folder, but I saw somewhere I shouldn't do this.

Then I tried to import addon-google_apis-google-8 as a project, but the project gives the error The import com.google cannot be resolved.

I'm following the Vogella Tutorial:

Activity:

SupportMapFragment fm = (SupportMapFragment)   getSupportFragmentManager().findFragmentById(R.id.map);
        map = fm.getMap();

         //map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
                Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG)
                    .title("Hamburg"));
                Marker kiel = map.addMarker(new MarkerOptions()
                    .position(KIEL)
                    .title("Kiel")
                    .snippet("Kiel is cool")
                    .icon(BitmapDescriptorFactory
                        .fromResource(R.drawable.btn_logo)));

                // Move the camera instantly to hamburg with a zoom of 15.
                map.moveCamera(CameraUpdateFactory.newLatLngZoom(HAMBURG, 15));

                // Zoom in, animating the camera.
                map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);

Manifest:

 <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <permission
        android:name="com.testmap.test.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" />

    <uses-permission android:name="com.testmap.test.permission.MAPS_RECEIVE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>  
    <uses-permission android:name="android.permission.WRITE_SETTINGS" />
   uses-permission android:name="android.permission.INTERNET" />
   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true" />

              <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="a_real_api_key" />
    </application>

I retrieved a_real_api_key by entering the SHA1 retrieved by installing the keytool plugin.. http://keytool.sourceforge.net/update fingerprint;com.testmap.test in the google console.

And xml:

 <fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.SupportMapFragment" />

I have the feeling I need to import the google-play-services library, can somebody tell me step by step how to do this in Eclipse, I've followed many answers, but I seem to do something wrong every time.

Yes, you are right. You need to import google_play_services_lib and add it as a library to your project.

For this, you need to:

Download the Google Play Services from the Android SDK manager
Add this as a project by "Importing existing Android Code Base". Go to ~/<android_sdk>/extras/google/google_play_services/libproject and add this to your workspace.
Once this project has been added to your workspace, right-click on it, go to "Properties" and then to "Android" tab and mark it as a library.
Go to your application, and then right-click to go to the "Properties" and go to the "Android" tab and in the Library pane, click "Add Library". This should show you the google_play_services project. Add this as a reference to your project.
Another requirement is to right-click on your project and go to the "Android Tools" option, and "Add Support Library...".

This should get the Maps running.

NOTE: We have to add the Google Play Services as an "Existing Android Code Base" project and not as a JAR.