CuteFTP for Windows or Fetch for the Macintosh are both adequate. The administrators username and password should be used for updating the main web site, or each user can log in under their name to update their personal pages. Please change your password occasionally, and keep it to yourself. With this password, anybody will be able to read or delete your mail, or change or delete you web site. We take security very seriously and will notify you if there has been any suspicious activity.
More information is available on the contact page.