in order to attach pictures, when you are posting, scroll down and you will see where it says "Manage Attachments"...click on that and you will be able to browse your desktop for an image or choose a specific url where your image is located...once you have your image, click upload and it should appear (if it is not too large).
You need to make sure the image is within the specifications for the site...if it is to large, you will need to re-size the image in order to fit the site requirements or it will not be uploaded to the site