This document provides an overview of the tabs and functions in the Sierra circulation module used at the service desk. It describes the Check Out, Checked-Out Items, Holds, and Fines tabs, explaining what information and options are available under each tab. Procedures for checking out different material types like Sinclair books, media, periodicals and OhioLINK items are covered. Other service desk tasks like renewals, holds, and fines are also summarized.