Basically the designer just sets up the editable regions throughout the page for certain divs, tds, etc.
The Content manager gains access to the editor for the page they wish to edit by clicking on the page they want to edit from the list of all their pages.
The editor comes up with tabs along the top, so the CM can just select a tab. TO make it easier for them you use the title or id tags to identify these regions/tabs.
There is no ability for them to edit multiple regions at once or formatting of the entire site. Most of my customers would destroy the site if I let them do that kind of editing. It may be possible to allow them access to edit a whole page by making the html tag editable, but I am not sure if that tag is editable or not. That is one of the restrictions with this CMS, you cannot make every type of tag editable.
It is purely for people who want control over the text and images on their site, e.g. it is cheaper and easier for them to update new course info themselves every few weeks.
It is ideal for small businesses who want to have a professional looking site designed properly and edit just the content of their site.