This is the code you want:
It looks like this but without the space after IMG ---> [IMG ]http://i464.photobucket.com/albums/rr3/budman3890/100_4353.jpg[/IMG]
What I do is get the pic that is the size I want to post and right click on it.
A menu pops up and I left click Copy image location (URL)
Then come back here and click on the little yellow mountain with a moon icon.
delete the http:// in the popup box then right click in the blank area and left click paste. Click OK.