As @Robert suggested, a CMS will work great in this situation. As for the platform, Wordpress is currently the most popular, well-maintained and extendable CMS with easy to use editor, even for someone with no technical background.
Update - Wordpress can be an overkill thought. If the site won't be edited that much and the changes would be minimal, you should look for another solution, @RK and @labsvisua gave some good ideas.