While I highly reccomend the Dune Novels by Frank Herbert, for the politics of the Dune Universe pre-Kwizats Haderach, the Dune prequels House Atreidies, House Harkonen, and House Corrino show HOW the Dune Imperium Worked (or failed to).
The Butlerian Jihad, Machine Crusade, and Battle of Corrin tell the story of how and why the wierd tech paradigms of the Dune Imperium come about....
Brian Herbert and Kevin J. Anderson do a wonderful job.
And we see, in Battle of Corrin, the origins of the Bengeserit, the first Mentat, Navigator, and Reverend Mother, and see the founder of the Suk School. Interesting to note: the Ginaz are the oldest of the "Big Schools" of the dune universe.
Dune and Sten have both influenced MTU strongly.
The Vorkosiverse would be a fun place to play in... too bad for me it's a GURPS product in progress... It has had little impact upon MTU, but happens to parallel a lot of the bits about MTU that existed before I encountered the novels.
Also, MTU has been shaped a bit by the Flinx Adventures series by AD Foster. Mostly in the negative. As in, "If it works in the Humax Commonwealth, it doesn't do it that way IMTU") Excellent reads, well paced, and a good model of a multi-racial hegemony working. The Universal Humanx Church is also an interesting nod to the Dune/Job/Dianetics apochyphal contest. (Apochryphal in the sense that I've never seen the proof myself; I've only seen second-hand or further removed, non authoritative materials referencing it.)
Also, Bug Life Chronicles (don't have to hand) has some really nifty stuff for those wishing to integrate Cybertech past the "implant" stage...
As general reading, the McCaffrey BB Ship series is an excellent study of a potential use of the cybernetic technologies to provide meaningful work-lives to the excessively physically crippled. (Note that it appears that the Killashandra series is in the same universe, as are Dinosaur Planet/Survivors, and the Lunzie Trillogy, and possibly also pern...) We know they have some form of hyperlight travel, but it's not discussed, and is apparently "In Prime Universe" rather like Star Trek and the Humanx setting, and unlike Traveller, Starfire, the Webberverse, and the Vorkosiverse.