The Rule of Thirds
The concept of the Rule of Thirds is to imagine breaking an image down into thirds horizontally and vertically. You will then want to frame your shot so that your elements are along the lines and preferably at one of the four points where the lines intersect to make your shot more interesting. New Shooters often want everything dead center in the frame. This is really used only when a person is directly talking to the folks at home. If a show host is looking at the camera and addressing the audience. If framing a person, their eyes shoot usually fall on the upper line. In the upper-third of the frame.
The Rule of Thirds is a great way to help you line up shots when you are being creative. Shooting B-Roll, music or other images that may not have a defined subject.
Good Luck and Happy Shooting!