If you have “Anyone can register” selected under Options > General, then when someone clicks the “register” link on your page, they will be sent an email with a confirmation link. Once they click that link, their initial password will be emailed directly to them without intervention on your part. The idea is that everyone’s password is secure, even from you. Of course, they can change it once they’re in (and if you’re an administrator on the blog, you can change their password, too).
However, the first initial login will have to be with the automatically generated and emailed password.
