Meditation is focused thinking. It takes serious effort. You select a verse and reflect on it over and over in your mind...if you know how to worry, you already know how to meditate.
Whether we realize it or not, we spend most of our life meditating on something. Every day you have reoccurring thoughts and a process by which you analyze and come to your conclusions. At the root, your thoughts are your meditations.
As I spent time doing some mission work in Toronto, I discovered a reoccurring theme in my life. Walking the streets of a major city causes me to meditate on where God is at work there. I find myself getting emotionally weepy and drawn to vision for the city. I begin to wonder if I am supposed to come here and serve God in some way.
It happened to me in Montreal, Saskatoon, Edmonton, Ottawa, London and anywhere else that I’ve spent more than a day exploring. The meditation of my heart draws me to a deep sense of calling and direction that God has put in my life. I have not been called to leave Windsor, but the calling of God is with me wherever I go.
So what are we talking about with Christian meditation? Richard Foster describes it in this way:
“Christian meditation, very simply, is the ability to hear God’s voice and obey his word. It is that simple. I wish I could make it more complicated for those who like things difficult. It involves no hidden mysteries, no secret mantras, no mental gymnastics, no esoteric flights into the cosmic consciousness. The truth of the matter is that the great God of the universe, the Creator of all things desires our fellowship.” 
Did you catch that? We are talking about the ability to hear God’s voice and obey his word. God desires to commune with us at a personal level.
In the Old Testament there are two primary Hebrew words for meditation: Haga, which means to utter, groan, meditate, or ponder; and Sihach, which means to muse, rehearse in one's mind, or contemplate. These words can also be translated as dwell, diligently consider, and heed.
Again, Richard Foster says,
These words have various meanings: listening to God’s word, reflecting on God’s works, rehearsing God’s deeds, ruminating on God’s law, and more. In each case there is stress upon changed behaviour as a result of our encounter with the living God. Repentance and obedience are essential features in any biblical understanding of meditation… It is this continual focus upon obedience and faithfulness that most clearly distinguishes Christian meditation from its Eastern and secular counterparts.
 Rick Warren, The Purpose Driven Life, Zondervan p.190
 Richard Foster, Celebration Of Discipline, Harper Collins Publishers, p.15
 Richard Foster, Celebration Of Discipline, Harper Collins Publishers, pp.15-16