There is a help page on every UnionCloud website at 

This page includes the following links: resend instruction mails

  1. Didn't receive activation instructions? 
  2. Didn't receove unlock instructions? 

You can point students to this URL for them to find out help on signing in. 

Registration and account help

A few things you might need to know

You can edit all of these questions in the backend dashboard under Admin > Setup > Messages and Emails > Registration Help.