Here is another good way to meditate if you have trouble calming your mind: Use a mantra. A mantra is a phrase that you repeat over and over again. This can be done in your mind or verbally. Traditional mantras are often in Sanskrit, an ancient language. You may have heard of "om mane padme om." You can also create your own mantra in English, such as "I am very relaxed" or "I love myself" or "Peace, peace, peace." Traditionally, mantras were repeated 108 times. That is why you see people with "mala" beads - these are necklaces that have 108 beads that you can count while meditating.
There's something deeply relaxing and rhythmic when it comes to meditating with a mantra. I always use the Gayatri Mantra when I decide to use a mantra at all; it's a bit longer than most, but it's beautiful and really opens me up in a powerful way. Sometimes it's hard to say it over and over in my head, so I do it to a CD accompaniment every once in a while.