What's the difference between published, private and unpublished for the guide status?
"Unpublished" is the default status when you create a new guide. The guide is invisible to the public and can only be accessed from the admin interface.
"Private" guides are only accessible to people who know the URL of the guide. People do not need to be logged in to the admin interface, but must know the guide URL. The guide is not visible on the homepage and not indexed for search, nor will offer a suscription via RSS..
"Published" guides are available to everyone and displayed on the home page under "Most Recent". Published guides are indexed for search. If RSS feeds are enabled, Published guides will offer an icon providing users the option to subscribe.