Hi Kazee, you might have already received your answer, but just in case, select the image, click the References tab [I’m using Office 2010 but the same instructions can apply to Office 2007] and in the Captions group, click Insert Caption. Move to the Label field, then click New Label button. Once a label name is entered, the default caption name will reflect the same name followed by a caption number. In the Position field, choose the desired position for the caption name, then click OK.
Just simply Right Click on the image and see the option Insert Caption you can click it and insert caption on it