It sounds like you have enabled the 'burst' function as described on page 103 of the camera manual.
To turn this back to single shot mode, press the Drive Mode button which is directly below the "Menu\Set" button, within the control dial. the icon looks like a series of stacked cards and a small stop watch.
Next you need to use need to use the control dial to select the icon which has a single box with no numbers inside it.
Press the "Menu\Set" button to save the change, then try and take a shot.
Please let me know if you need anything clarified.