Open a photobucket account. Upload a photo to your photobucket account. Copy the image/photo file in the right hand margin of your photobucket and embed in your post.
You'll see it the image/photo in photobucket as it has 'IMG' in square brackets either side of the file name. Embed the whole link (including the IMG in square brackets either side of the file name) in your post.
I believe there's a sticky on this but can't see it as I'm on tapatalk. Someone I'm sure will post a link to it.