If the picture is already on the net say on another web site Right Click on the picture, select Properties, copy the URL, then past it like so...
[img=http://www.trdparts.jp/english/image/list_altezza-f.jpg]
Have a read of this if if that didn't make any sense... http://www.tips4pc.com/Internet-tips/how_t...of_an_image.htm