Hi,
This can't currently be done I'm afraid - in order to edit pages using the CMS a user needs Admin rights on the site.
It's something we'd like to implement if there is sufficient interest - at least perhaps allowing editors to use the "Quick Edit" functionality without being full site admins.
Currently you can configure it so that members can upload photos, contribute to discussions, post on the noticeboard/weblog, add events, add classified adverts, etc but not edit content pages.
Thanks
Joe - Voice Admin