Thats very easy mate... Look
To post an image just set [*img] before the URL of the Pic, and close the hole thin with [/img]
To post an URL its just the same, open it with [*url] Than type the URL behind, and close with [/url]
Hope I could help
*** LET THE STARS (*) out, or It wont work ***
If you have no server to upload your pics, use
www.imageshackus.com It's free!