Hearing God is not all that difficult. If we know the Lord, we have already heard His voice - after all it was the inner leading that brought us to Him in the first place. But we can hear His voice and still miss His best if we don't keep on listening. After the what of guidance comes the when and how.
Is That Really You, God?: Hearing the Voice of God (ed. YWAM Publishing, 2001) - ISBN: 9781576582442