The Naked Sun is the sequel to The Caves of Steel, and like that is a detective story set on the featuring robot-hating Plainclothesman Baley and, as if to prove Asimov really could predict the future, or movie-making of the '80s anyway, his entirely unsuited partner R Daneel Olivaw, a robot. Unlike CoS it's set on the (spacer) planet Solaria, a planet of few people and many, servile, robots.
I was a little disappointed after reading CoS, and was expecting something of the sort here, but that didn't happen. CoS was set on an Earth which I found awkwardly described - you got the impression Asimov was trying to say things about the way people thought but couldn't quite get them out. No such problem with The Naked Sun, where Baley's future-Earth foibles are out in the open (figuratively and literally), and Asimov also successfully hints for the first time that a utopia made up of a world where everything is done for you and where people can live for hundreds of years may, possibly, be flawed, a thesis that becomes stronger in "Robots of Dawn" and "Robots and Empire."
Asimov wrote that CoS was an attempt to answer a critic that it was impossible to combine the genres of science fiction with detective stories. The Naked Sun is much more than an answer to that challenge, it's one of Asimov's earliest studies of humanity, and it's a well written thoroughly readable one at that.