I highly recommend Michel Hoellebecq's book HP Lovecraft: Against The World, Against Life, for an excellent critical/philosophical assessment of Lovecraft's work.
From The Writer's Almanac:
It's the birthday of H.P. Lovecraft born Howard Phillips Lovecraft in 1890 in Providence, Rhode Island. He wrote science fiction, fantasy, and horror, a genre that during his life was called simply "weird fiction." Lovecraft wrote hundreds of poems and short stories, but they were scattered throughout various pulp magazines and publications. It was only after his death that some of the people he had corresponded with in letters were determined to share his work with the public, so they formed a press called Arkham House specifically as a way to publish Lovecraft's work. They issued The Outsider and Others in 1939, and his books are still widely available— books like The Dreams in the Witch House and Other Weird Stores (1932). Fantasy and horror writers like Stephen King and Neil Gaiman consider Lovecraft one of their major influences, and Jorge Luis Borges wrote a story, "There Are More Things," in memory of Lovecraft.