Global settings can be configured via the global settings admin in the CMS under the "Content Review" tab. This includes global groups, users, as well as a template editor that supports a limited number of variables.
To set up content review schedules you need to log in as a user with the 'Set content owners and review dates' permission. This can either be an administrator who has all permissions, or by giving a group the specific permission.
To set a content review schedule for a page go to
Settings > Content Review.
CMS users without the permission to change the content review schedule can still see the settings and previous reviews in the same view, but cannot change anything.