WordPress has 5 built in user roles, Administrator, Editor, Author, Contributor, and Subscriber. These roles usually cover most needs, but you may have a need to allow users to edit existing pages/posts and create new content, but you may want to allow a site administrator to review those pages/posts before publishing them. You can add that functionality and more using the Wonder Twin plugins Role Scoper and Revisonary.
This video will walk you through what these plugins do, and how to configure them.
Click on the image to view the video. Quicktime player 7 is required.
Tags: editing restrictions, user roles