New users can't sign up by themselves; only the admin can. Is it possible to customize the email that goes out to the new user so that it includes a link not only to the WP login, but the page they went to that was protected that they are going to want to get right back to?

We have a user guide. It's password-protected with RS. New users get to the page, it says you need to login, here's the link. Clicking the link takes them to the WP login. Or, if they use the email the receive when I sign them up, they probably don't know what to do next. So… I need to know if I can customize that outgoing new user email with additional instructions, additional link, and possible set it up to CC our support email.

Is this possible? Can it be tied into each role group, i.e. an email to someone assigned to one role group would have their useful links, while an email assigned to another role group would have their necessary link.

Thank you for your time.