In Word 2007, you can quickly add captions to your graphics by using the Caption button on the toolbar. This button allows you to add a caption for any image or text that appears in your document. To add a caption, click on the Caption button and then type a caption into the text field. The Caption dialog box will appear, and you can choose from a variety of caption formats. You can also use the Caption button to insert a caption into an image that is already in your document. To do this, click on the Image button and then select the image you want to add a caption to. The Caption dialog box will appear, and you can choose from a variety of caption formats.
Select the picture or graphic you want to add your caption to. Click the References tab on the Ribbon, Choose Insert Caption, click the New Label button and type in your caption.
This will bring you back to the Caption box and as you can see the Caption and Label fields are populated. Click OK one more time.
Word applies the caption to the image which I highlighted in green. You can use this for any type of image in your Word document.