Theodore Sturgeon was born Edward Hamilton Waldo in New York City in 1918. Sturgeon was not a pseudonym; his name was legally changed after his parents’ divorce. After selling his first SF story to Astounding in 1939, he travelled for some years, only returning in earnest in 1946. He produced a great body of acclaimed short fiction (SF’s premier short story award is named in his honour) as well as a number of novels, including More Than Human, which was awarded the 1954 retro-Hugo in 2004. In addition to coining Sturgeon’s Law – ‘90% of everything is crud’ – he wrote the screenplays for seminal Star Trek episodes ‘Shore Leave’ and ‘Amok Time’, inventing the famous Vulcan mating ritual, the pon farr.
Under normal circumstances, we’d unhesitatingly recommend starting with an author’s SF Masterworks titles – in this case, More Than Human:
However, given Sturgeon’s incredible body of high-quality short fiction, you might be better off starting with volume one of his Complete Stories, The Ultimate Egoist, and then going back to More Than Human before continuing with novels The Dreaming Jewels and Venus Plus X: