Hi, Singh. There are two ways. You can attach your photo (when starting a thread you will see a paperclip below and a link for "Attach files" or when replying to an existing thread click on "More Reply Options" and then you'll see the paperclip link there. Clicking on "Attach files" allows to attach your photo stored on your computer or storage device, etc. The other option is you can upload your photo to some photo hosting site (I've been using Google+ lately). Then, instead of the "Attach files" option at the top of the reply box you will see am image that looks like a tree. Click on that and then paste the URL for your hosted image.
Jon, maybe you can clean up this explanation and include it in your sticky thread for tips, etc.