People can be listed by clicking the "People" menu item on the organization sidebar.
You can filter and sort your People.
A user must first sign up to workbench before being able to be added.
A user may gain access to Workbench by visiting workbench.import.io. If they do not have a valid session, this will then redirect them to GitHub to ask them to login/signup and connect their GitHub account to Workbench.
By default a new user will have no orgs that they can access, they have to be permissioned into them:
The My Account page shows their user id:
There are currently two organization roles: ADMIN and MEMBER. An ADMIN can list, add and remove users to the organization, and change their roles.
You can change the role someone has in the organization by selecting the role in the drop down.