If you're linking a picture from another site, put [img] before the link and [/img] after. Otherwise, under 'Go Advanced' there's a paperclip you can click on to upload.
"What, exactly, is the internet? Basically it is a global network exchanging digitized data in such a way that any computer, anywhere, that is equipped with a device called a 'modem', can make a noise like a duck choking on a kazoo." - Dave Barry