Lose 1D4 sanity.
He's really not much of a looker and honestly go spend ten minutes on wikipedia and you'll know more about him then most people do. His life story while interesting isn't what's important. It's all about the tons of short stories he wrote. They may not be your cup of tea but they have to be at least respected considering they had a major influence on most horror you see today. If you don't know Lovecraft you've probably seen a hundred references without realizing. If you enjoy reading here is a list of his most famous (not best) stories. Also take note these are the years they were written not published.
The Statement of Randolph Carter 1919
Herbert West-Reanimator 1921-1922*
The Rats in the Walls 1923
Cool Air 1926
The Call of Cthulhu 1926*
Pickman's Model 1926
The Dunwich Horror 1928*
The Whisperer in Darkness 1930
At the Mountains of Madness 1931*
The Shadow Over Innsmouth 1931*
*I'd say these are arguably the most famous and if you're only interested in not being left out when the elitists and hipsters start talking about how cool and unique they are for liking Lovecraft I'd start there.
Well that's all I'm going to say for now I'll probably doing deeper reviews or synopsis if you just want to know what they're about without actually reading. Oh also his universe is referred to as the Cthulhu Mythos. Cthulhu is by no means the most powerful or even cool creature. What you should know about him is people say "Cthulhu Ftagn" to cheer for him, he is currently sleeping in the sunken city of R'lyeh, will arise when the stars are right, and is commonly thought to look like this.
People really like him.