I’m pleased to see there was a good encyclopaedia for Dune, back in the 1980s, Dune Encyclopedia. It was written as if ‘in-world’, and as such felt free to elaborate new ideas on the background and character back-stories. Today it can be understood as a possibly-correct history, with errors and misunderstandings made by some of the ‘historians’ involved. This is because Herbert himself later contradicted some of the elements in the Dune Encyclopedia, with his later Dune books.

Note that the new Dune Companion book from McFarland is apparently a stinker, and is to be avoided.

After a little digging and testing I find that the reading order for unabridged audiobook readers is:—

1. Book 1: Dune. The unabridged audiobook reading by George Guidall is the best one to listen to. Also, note that the Scott Brick audiobook version is apparently abridged for some reason.

2. Interlude: “The Road to Dune”. A quite short work by Herbert that sits between the first two novels, to be found in his short-story collection Eye. There appears to be no audiobook of this, so it would need to be read in ebook form. Said to take the form of “a guidebook for pilgrims to the planet Arrakis”. (Update: A Scott Brick / Audio Renaissance audiobook titled “The Road to Dune” was released in 2012 – some say 2005 – but apparently it does not actually contain “The Road to Dune”!).

3. Book 2. Dune Messiah. The unabridged audiobook reading by Scott Brick et al.

4. Book 3. Children of Dune. The unabridged audiobook reading by Scott Brick et al. is the most listen-able.

There is also a Book 4, God Emperor of Dune. It’s by Frank Herbert, rather than some later cash-in writer. But it is widely said to be a rather depressing and dour coda to the original trilogy. It also departs heavily from the style of the core trilogy. As such, you may well be happy with just the original trilogy.

Note that each of the three core books appears to have “Deleted Scenes & Chapters from…” fannish ebook floating around the Internet, which might be looked at after each novel. Some of these are in audio as part of “The Road to Dune” audiobook mentioned above.