Your pictures have to be hosted somewhere first. I have my website where I put pics on, but its funny I cant bring them up on here, I have to post them on my personal section of the RTOC website, and you link to them from here...like this for example. You have to insert (img) tags first and enable HTML
(img]http://www.rtoc.co.uk/mypicture.jpg[/img)
Click on Img tag button first, enter image address, and then click Img again.
On the RTOC window, right click on the furthest bottom right that you can, and bring up properties. It will say the filename like DYIEFBIYEQYTITIYG.jpg. Copy and paste that with the img tags. You nearly had it, but you for got the .jpg at the end.