Through the Users page, you can view and invite your team members. You will have the ability to configure the access you desire for each person.
You will need the first and last name as well as the user's email address. When you invite a team member, you will get to pick the role: Administrator, Manager, or Contributor. You can find out more about what the various roles entail, here. If you are a Contributor, you cannot invite other team members. A user needs to be a Manager or Administrator to invite other users.