First click the Host an image box
Then find your pic by using browse button. Choose the size you would like it to appear or choose no in drop down box.
Then right click Image url and copy.
Now click image button.
Now paste Image Url in this box and click ok.
If you have done it correctly it should post the image you copied to the page and will look like this before posting.
If you wanna place more then one pic in same session you repeat process except on host box you click upload to get original screen.
hope this helps. Remember practice makes perfect.