When you want to post something and get the "post reply" screen, down at the very bottom is an item marked "Attachments and other options". Clicking on that will open up additional space below it that includes "Attach:". Use the "Browse" key to find the directory you have the photo in and the pix itself. When you have selected the file that's your picture click on the "open" button there and you should come back to the post reply screen with the file name in the attachment box. If you want to post more pictures after the first one, click on "(more attachments") to load another. Note that the maximum file size for 1 picture is 5 MB and you have a limit of 13MB for the total size of postings (limit of 4 posts per reply).