To add a picture in a post click on the little tree icon and paste the url in there.
Your find the url of a picture by left click when on the picture and select properties...copy the url and paste it.
and you'll get the picture.
This pictures url is http://www.jpcycles.com/Content/images/30logo.jpg
clicking and pasting that url in the box get you this:

However please don't post pictures in the forum unless it's something you need a tech to look at ..or to show a problem.
That's what your "My Files" are for in your profile (which it looks like you've got that part figured out and uploaded already).
Hope that helps.
Don't forget to check out the Gold Club Benefits