I've recently built a site for a realtor (www.cornettrealtors.com) that wanted to be able to add listings and edit certain pages. I've accoplished this by using various CGI scripts that can be found at http://www.cgi-resources.com/Programs_and_Scripts/Perl/ . Problem is, people want to be able to edit a site but don't want to learn how to do so. I tell most people that any site is editable by three methods.
1-take the time and effort to learn how to create and edit HTML code, THEN learn how to use an HTML editor
2-pay the money it takes to have the kind of programming done that makes a site editable
3-pay a firm to do it for you