Every page of your organization can be headed by your organization's banner. Just upload a banner image under your page named "Banner.jpg", so that it will appear in the following url:
(the banner is therefore expected to be in jpeg format) and the system will automatically display it on the top of each of your pages, including on the front end site !
We are also planning to include support for html banners, which therefore might include both images in arbitrary format, and text that can be selected and accessed by search engines. They will be expected to be found at a location like the following
(where "Banner" is a standard wiki page containing some html)