go to a hosting site like
www.imagestation.com and load up your pictures and it will have a link for the picture
on here type:
[IMG ]picture link[/IMG ]
(but no spaces between the G and ])
or when you reply on the post reply page there is a IMG button on top, you can just click on that button and copy the link
Oh yea....if you do decide to use imagestation, in the link delete the .img.jpeg (or something like that, I haven't used it for a long time) at the end of the link so the picture will show up.
Hope this helps