To Add a New User
Click the "Add New User" link button at the bottom of the page. Use the users email address as their username as it is unique, and will be easy to remember. The add user form allows you to set their username, email, location, and password.
To Change/Reset a Password
Click the users' username, in the lower right corner of the users profile click the [Manage Password] to set (if the [Unlock Account] button is popped out, click it to unlock their account). The user will be emailed a copy of the password.
Walking a User Through Changing Their own Password
All users have access to My Profile. On the My Profile in the top right corner there is a link button "Change Password". Click the "Change Password", complete the form, and click [Change Password] to save.