Can you see the little box with the mountain and sun beside the symbol of the earth with a little two link chain under it? (it's in the Quick reply and post reply boxes) You click that and insert the URL of the place where you've hosted the image.
Was I answering the right question? Also, since you're new, Welcome!! And if I come off like I'm teaching a kindergartener - that's what I used to do and so I tend to help in the most simple of terms possible - it's nothing personally directed at you!