Enable select users to add pages to defined area of site

Hello, On my site I have about 7 different areas that cater to different groups. I would like to be able to have a named member from each group be able to simply add content (pages) to their groups area. I am not too sure how go about this.

Can you point me in the right direction?

(please keep in mind that these folks are very computer un-savvy, so it would have to be pretty simple)

Thank you