Let's say you want to add your other members of your sales and warehouse team on a project.
If you click Team in the top right of your screen you'll see a list of your users.
From here you can click 'Add' to invite the user, or 'Remove' to remove them from the project.
When you add an additional Full User to the project, you can then change who the sales lead is on the project.
When invited to a project, your team will receive an email notifying them that they've been added.