Just seeing this now, so it may be too late. The thing to note about Lovecraft is that he wrote in a heavily literary style with lots of elaborate descriptions. So you might want to start with just one story and if you like that, try a couple more.
"The Dunwich Horror" was the inspiration for the DS Leviathan storyline--and was made into a fun film (well, *I* think it's fun) with Dean Stockwell, Sandra Dee and Sam Jaffe around the same time (1970).
A couple more that I think are good: "The Call of Cthulhu," "Dreams in the Witch-house," and "The Whisperer in Darkness." I remember "Through the Gates of the Silver Key" being bizarre and fun but it's been around 30 years since I last read it. It's described as being co-written by HPL and another writer, but the other writer only contributed one paragraph--which I believe HPL completely re-wrote so the style would match up.
Best, G.
