The Add and Edit Member screens are identical.
The only required setting for a member is the email address on the Members: Add Members: Add Member: Basics tab.
If you'd like this member to also be a list admin, fill out the required information under List Admin, and also the Password under Settings.
Note that the total number of members you may have on your server is determined by your license. Contact your account representative at sales@lyris.com if you'd like to increase the number of members you may have.
For a video tutorial on Adding a Single Member, click here.