Creating new users and giving them appropriate rights is fairly easy. Just go to your top right drop-down menu and click Users. Use the orange button to add a new user. Type in your user's email address and choose one of the few user types.
There is a description below of each user type. However, if you want more control, choose a custom user. This will allow you to control every part of your account.
After you are done, the user will need to click on the confirmation email and log into his account. That's it! Your new user with custom rights is now active.