Copy. You need to open a off site account for photos (I use photobucket). On photobucket you upload your photo. When the photo is opened over to the right you will have options for sharing. Here you copy the link for Direct. Then you come here to post your post. Use the image button directly above on the post tool bar. A pop up will show up and you paste that link into the pop up and press ok. There you have uploaded a photo for all to see.
Or refer to the post above mine for detailed instructions with photos.