Start with some of the classics: Asimov (I Robot), Bradbury (The Illustrated Man, Martian Chronicles), Clarke (A Fall of Moondust) These stories are both good examples of sci-fi but also good examples of storytelling. In I Robot the Three Laws are a wonderful premise for stories that have spawned a wide following. In A Fall of Moondust a simple physical fact and its implications for human survival become captivating suspense. The early works of Heinline like The Past Through Tomorrow what technology does to our humanity. I'd suggest that you begin with shorter works and work towards one longer work, however Dune, or Stranger in a Strange Land are not good first semester works, nor would hard scifi like Forward. Nourse's The Universe Between, L'Engle's A Wrinkle in Time are great for younger kids but probably too simplistic for High School. Explore where technology puts us into unusual situations and how those situations impact our humanity. Dick's Do Androids Dream of Electronic Sheep - where do we draw the line of what is and isn't human?. Maybe throw a changeup with a book that really explores what it means to be alien like Brin's Uplift series (Startide Rising) or Cherryh's Chanur series (Chanur's Venture). Or some Gibson. Let the stories awaken their minds to new possibilities, after all that's what its all about.
