If you already have them on your hard drive, you can just click on the Additional Options below this box. You can upload it directly from there if they're not to large. After clicking on the additional options, You will see the word Attach in bold letters. Click on the browe and it will send you to your photos on your hard drive. Then beside the browse button, you see more attachments. You can put up to 4 photos this way.
Or if you have them linked on a website, or pic hosting site you can put more. Like photobucket or something. I can do this, but hoping someone else will explain it. If not I will try later.
Kim