If you would like a photo to be part of your signature, just click on 'my settings' and scroll down to edit signature. From there go down to option 1 or 2: Option 2 lets you upload a photo from your computer. Just click on browse til you find the photo you want from your computer and click on it. Then make sure to hit save when you are done. Your signature and photo will show up in your first post of every thread that you may reply in. Hope that helps.

EDIT:
your photo showed up in all your posts since you put it under your screen name box.

I think you are all set now...