I have to say that, for the amount of work you've done on it, I can't see the join which is definitely a good thing!
When it comes to posting an image, you need to find the address of it. If it's in the gallery here you have to click on the enlarge button (the magnifying glass over the top right of image), wait for the image to pop up, right click on it and select the address.
To actually get that into a post there are a couple of ways but personally I use the "tag" system. To get your picture in this thread I typed in this (exactly and with no spaces):
[img]http://www.photoradar.com/files/imagecache/original_large/photos/users/hughredcanary/dsc-3790-e-2.jpg[/img]
This is the address of the image surrounded by [img] and [/img]
Hope this helps - there is more info on tags
here