At the bottom of this page is a cheatsheet you can use. 
It's the 3rd code on the bottom

HOWEVER, i suggest you save your picture and upload it to tinypic.com and use the image code it gives you from that. It works better for me. 

check this tutorial out i just made

[hider=Guide To Posting Pictures Via TinyPic][IMG]http://i62.tinypic.com/8zlen9.jpg[/IMG][/hider]