To put a picture to the left of your posts, (your "avatar"), click "my profile" at the top right of this page.
Scroll down to "my avatar" and check the "upload my picture" option.
You will get a browse box and you can load the picture from your computer into the system. I think it has to by 145x145 pixels and less than 8kb maybe? It helps if you get your picture all sized and ready first, then just choose it when that option comes up.
After you load the picture, scroll down and click "apply", then when the page refreshes, pick "OK".
To add a signature, go to the same "my profile" page, type in your signature, click apply and OK again.
Hope it works for you!
Change occurs when the pain of remaining the same outweighs the fear of the pain of change.