actually, the site software uses pretty standard UBB coding.
Images have to be "hosted" somewhere like picasa, photobucket, etc as a jpg. (ie, uploaded from your computer to photobucket's server)
On photobucket, each picture will have an address www .photobucket/mypic.jpg
On this sight, the picture's "address" is surrounded by [img][/img] (no spaces). Done thusly, it'll load the pic automatically.
it looks like this(delete the spaces) [img ]
www.pb/mypic/jpg[/img ]
finally, sites like photobucket usually have a button called "copy IMG code" or "copy embedding code" so you can click & paste without typing anything at all.