Click on the host an image icon (looks like a picture with a disk in front of it)
click on browse
Find your picture, click okay then host it
Pick your size image and click copy
click on the host image icon to to minimize it
right mouse click on the page and click paste
you won't see the image, but the file name.
click preview an you can see the image before you post
Hope this helps, feel free to ask if I at all confused you.
you might have to sign up to get a free account before you upload you pictures. I did it a wile ago and have had no issues.
Happy posting!!