First you have to upload the picture onto the web. You have a gallery here that you can use. Click on the 'gallery' link on the left panel of the page. Then click on 'my stuff' on the link panel across the upper part of the page.. and go to 'my gallery'.

Scroll down a bit to find the quick upload. Select your pic, and upload it.

Then it'll go to a page with your pic on it. Right click on the pic and 'copy image address'

To put the pic in your post, type [ img ] paste image address here [ /img] -just take the spaces out from the [ ]'s