Stewards serve in a voluntary capacity. Each department/unit may select at least one steward. An important piece of being a good steward is to listen to your colleagues and share any concerns with union leadership or staff. It is also possible that a colleague may ask you to accompany them to a meeting. United Academics has developed a form to help you along with both of these important union activities. You can find that PDF here.
Click on the image to view the full United Academics Stewards handbook. Additional information about being a steward can be found here in the Bylaws of United Academics.