or you can put it between [ img ] place photo url here [ /img ] Taking out the spaces. Use the square brackets with img inside it and then your photo url(address) and then more square brackets with /img in them after the address. This is the HTML code for posting photos here. I have turned the HTML editor on so you can use it here.
Another quick way to do that is to click on the image icon which is the third from the right that looks like a photgraph. It will put the img brackets up automatically for you and you just insert your photo url by pasting it inbetween them.
Let me know if you should need more help with this. The photo and disk I don't know what that is yet (4th from the right)
And apparently the film strip one you can insert video from youtube into your post. I haven't used this feature before either. So you can experiment with things and we can learn from each other.