First have a look at the 'EGO very short guide to the workarea'.

In addition there is a useful excerpt from a rather extensive manual of Plone, the editing software on which is based the workarea.

Making new WG3 pages

By default please add new pages to the WG3-Topology folder and images to the WG3-Topology/image_dir folder.

Once a new pages is linked from the main page, please remove it from the navigation bar by doing the following:
go to the new page (you need to be logged in), then click on 'properties' in the top (green) navigation
bar: a new page opens in which you can set a check box 'exclude from navigation'. Please do so and
press save.

Playground

You can use this Playground page for testing all this.