I've used Drupal from the ground up, and am going to at least do some content editing with Joomla (probably eventually some styling). They're great for simplifying content editing, although the biggest snag that you'll have to train the users not to just copy and paste from Word -- it's nice to give them a WYSIWYG text entry window, but generally all kinds of stray coding will be imported from Word.

Definitely a learning curve involved in creating a site, even after having done complicated things with code. It's a different language. Fortunately, my work is at a university, and they provided free workshops and a discussion listserve for Drupal.

I'm afraid that I'm not at a stage to be able to compare between CMSs.

Consider whether what you'll want to create might fit something blog-oriented, like WordPress. Less flexible, but less complicated, is my understanding.

~ Becky in Tucson