If you are an adult leader you can view the merit badges for which you are registered by going to My Stuff --> My Merit Badge Assignments.

This will display all of the merit badges for which you are allowed to assist scouts, as shown below.

Click Update on one of the merit badges to view the details.

From this page you can update your comments and availability date.

Click Add Scout For This Badge to select a scout who wishes to begin work on this badge.  This will add this badge to their "in progress" list.

Click View All Scouts For This Badge to view all active scouts who are working on this badge, including those for whom you are not assigned as their merit badge counselor.

The lower portion of this page shows the scouts who have signed up for you to assist them with this merit badge.

Click Update next to a scout to sign off on his requirements, as shown below.

Click the check box for each requirement this scout has earned.  If the requirement was completed on a different date, enter that date in the Earned column.

Click Save & Exit to save your work.