CMS Tutorials

For an overview of CMS for a non-technical audience, try James Robertson's excellent site:
http://www.steptwo.com.au/

Also try:

http://www.designit.com.au/articles/rebuilding_gradlink

More CMS Tutorials

The new CMS Wiki has a definition of a Content Management System.
http://www.cmswiki.com/tiki-index.php?page=ContentManagementSystem.

It also has a discussion of the confusing term portal.
http://www.cmswiki.com/tiki-editpage.php?page=Portal

And something on Workflow.
http://www.cmswiki.com/tiki-index.php?page=WorkFlow

CMS Review has references to all the great books on Content Managemant.
http://www.cmsreview.com/Resources/Books.html.