I tried to start the Golf this morning, but all i got was a high pitch squeal from the starter motor/solenoid area, this continued even when i removed the keys

The only way to stop the noise was to disconnect the battery! Is this a common problem? Is there any tips before i get a new starter? Hit it with a hammer?

Is there a idiots guide any where to removing/fitting a new starter, i read somewhere that it is connected to the engine mount?
Thanks