You can add a caption to a photo when it is uploaded. When you add the photo to a page in the yearbook it will include the caption. While on the page you can edit or remove the caption.
1. Click on the photo to get Image Options. In Options select Caption.
2. Select Edit Caption if you want to edit the text. You can also edit the Font, Font Size, Alignment, and Color. If you decide that you do not want to use the caption you can turn it off.