Not the easiest content management system to learn (not as intuitive as others), but very customizable thanks to the large number of templates, modules and plug-ins available many of which are free or reasonably priced. Lots of info (updates, add-ons, forums, etc.) at www.joomla.org/.
Great Content Management System (CMS) for web site management. Front end is the web site, back end has html processor for entering content. It is Open Source, and there are many books teaching how to use Joomla! Even a video "Quick Start Guide" help.joomla.org/ghop/feb2008/task167/index.html