Two great but very different science fiction authors were born in May: Harlan Ellison and Ursula Le Guin.
Ellison, an endlessly creative annoying man who’s on his fifth wife, has written a multitude of novels, short stories, essays, screenplays, criticism, and more, and has served as consultant for movies and TV series. (In an episode of Babylon 5, he basically played himself as the supremely irritating computer voice.)
Take a look at Harlan Ellison: The Edge of Forever, a biography whose introduction is available online, or a selection of his writings in The Essential Ellison.
Ursula Le Guin has also written vastly different types of works – she is the award-winning author of novels, short stories, poetry, children’s books, screenplays, and criticism, and is mentioned in at least 28 doctoral dissertations. Many of her works demonstrate a strong feminist and/or political viewpoint.
Lists of Le Guin’s writings, interviews, awards, photos, and more are on her web site, whose home page is a map of the islands of Earthsea. The library has quite a few books by and about Le Guin (including my favorite, The Lathe of Heaven).