I'd agree with doing it with a database if at all possible. Most of the sites I've built in my time have been DB driven and in my experience it makes like a lot easier.

Probably the most important thing is to not let the user touch anything directly (you don't want them in the actually DB interface or writing directly to a file just in case they end up putting something in that your output system doesn't like) - if you write a set of HTML forms to enter the content and validate it before it gets anywhere near storage you should be fine.

In short - if you have access to a DB, then I'd always use it in preference to static include files.