How do I use the ribbon to insert pictures?
From what I am seeing on their official website, it appears that the portal leads to multiple pages that open other portals. It's impossible to say exactly how the images are added since it might be possible that each portal is controlled by an administrator. Try getting in touch with the administrator and he will tell you the exact procedure to do this.
I've found a contact page with details you can use: http://www.cms.k12.nc.us/Pages/contactus.aspx