Add them in your dashboard. Up to ten people can have access at no extra cost, each with their own login, so you never share a password.
The steps
⟨to add: adding a person under Account, with screenshots⟩
What each person can see
⟨confirm: what a person you add can see and change, and whether access can be limited to one site⟩
Taking access away
⟨to add: removing a person⟩