As an amateur, most people will pick up the camera and hold it in the typical lateral position for nearly every shot. This "landscape" orientation often produces very acceptable images but in some instances, turning the camera on end for a "portrait" shot is the better choice. For those with very limited experience with their digital camera the decision as to which orientation to use can be confusing.
Certainly, photographers can get quite creative and take shots of people at a variety of angles to provide greater interest. Experimentation is not to be discouraged. However, for more reliable results, the traditional orientation of portrait or landscape is typically recommended for beginners. Which way the digital camera should be oriented generally depends on one of two things: the subject's position or the movement of the subject.
One of the basic rules of photography is to focus on the subject and to reduce the appearance of other items in the frame which will distract from the subject within the image. Sometimes orienting the camera differently will allow the photographer to eliminate the distractions without stepping in closer or cropping the image later. For instance, if the subject is a person standing, most often the orientation of the camera should be portrait. This will result in fewer distracting details showing up to the left and right of the person standing in the picture. However, if this same person is reclining, the orientation of the picture should generally be landscape. This will eliminate more of the dead space or distracting items from above or below the subject.
Another example would be in nature shots. If the subject of focus is a single tree, a portrait orientation would be effective in reducing some of the extraneous objects to the left and right of the subject. On the other hand, if the subject to be captured is a gradually sloping mountain or the front and side of a covered bridge, a landscape orientation would be more appropriate.
The movement of the subject is the other factor that should be considered when determining which way the camera should be held. If the subject is moving left to right, a landscape orientation is more often the optimal choice but if movement is upward or downward, portrait orientation often works best.
For example, if the subject of a picture is to be a dog walking along a line of rail road tracks and the photographer wishes to capture the movement looking down the track off into the horizon, a portrait orientation best demonstrates the movement. However, in the same scene, if the aim is to show the animal moving horizontally, versus off into the horizon, a landscape orientation would be preferable. In this case, it is not only the subject but the direction of movement of that subject that determines how the image will be best captured.
As with any rule, there are instances where these traditional guidelines can be violated with great results. However, in most instances adhering to these guidelines will allow the beginning photographer to capture images with their digital camera that they will be proud to display.