There was a great answer to how users can manage their posts only from the back-end. What I am wondering, is how to allow users to only see their posts, pages, etc, which have their user id attached to it. I'm applying this to custom post types where the users manage their uploaded media.
You can manage roles and capabilities using this plugin http://wordpress.org/extend/plugins/capsman/
You can even add roles and capabilities as well http://wordpress.org/extend/plugins/capsman/screenshots/
Also the settings page of this plugin is under Tools>Capability Manager