Legends of Dune, Book 2. Ten thousand years before Paul Atreides is born but shortly after the events of Book 1 as the Butlerian Jihad's events continue.

Dune: House Trilogy, Book 1. This takes places a couple of decades before Paul Atreides is born. This series covers everything right before the events of Dune take place and gives you a new, fresh look at many of the original characters including Paulus (Paul's Grandfather), Leto, Duncan Idaho, Baron Harkonnen, and many others.

Legends of Dune, Book 3. This wraps up many of the events leading to the birth of Paul Atreides. Many questions are answered and some are left to be answered by the original series written by Frank Herbert.

The Dune Chronicles, Book 2. Paul Atreides, the Kwisatz Haderach, has assumed the emperorship from the Corrinos. Not only does Paul grow up, but so does his sister, Alia. This seems to be the book that sets the stage for the six books that follows.

The Dune Chronicles, Book 4. This takes place 3,500 years following book 3 at the end of Leto II's reign as Emperor and tyrant of the universe. This is when the gholas of Duncan Idaho becomes more of a central figure of the story as one after another serves the God and Emperor, Leto II.

The Dune Chronicles, Book 6. Unfortunately, this book was the last written by Frank Herbert before his passing. Miles Teg is dead as is the world of Arrakis but the Bene Gesserit attempts to bring them both back. Arrakis in the form of a new planet called Chapterhouse, which the Bene Gesserit turns into a desert planet and Miles Teg in the form of a ghola like the other Duncan Idaho gholas.

The Dune Chronicles, Book 8. Finally, the wrapping up of the entire series. This takes off right after the events of book 7 as the ghola children grow up, recover memories, and prepare for war. Little of the questions set up by Frank Herbert are left unanswered.