First you need to find the image you want(TeamSD image), point to it with your mouse cursor, then right click on it. next, click on "properties" and you will see the URL address. highlight and copy that address.
Now open your "profile" and on the left hand side, click on "forum profile information". Now go down to the area marked "Signature" and "paste" that URL address you copied.
You will now have to put [img] tags before and after that URL address.
It will look similar to this--> [img]http://yourURLaddress[/img.] (except don't add the period in the last "img" bracket. I added that so it would show up for you to see)
Then click on "change profile" in the lower right corner of the page. you may have to type in your password then for the actions to take effect.