Most likely, the camera is in the wrong mode.
For daylight outdoors shooting, set the mode dial to '''AUTO'''. If the images still turn out too bright, check the ISO setting: press the '''ISO''' button and make sure it's set to '''AUTO'''.
Another reason why the images may ''appear'' excessively bright, is the LCD brightness setting. If the LCD brightness is set to '''Bright''', images may appear brighter than they really are when you view them on the camera's monitor. Setting the LCD brightness to '''Bright''' makes sense when you're viewing your images outdoors in bright sunlight, but otherwise it's best to leave the LCD brightness set to '''Normal'''. Press the '''MENU''' button, select the '''Set Up''' menu, and check the LCD Brightness setting.