What H.P. Lovecraft Book Should I Get?

Ok, so I just heard about him and I want to read one of his books, especially one that explains Cthulhu and the Necronomicon (is that how its spelled?) because I feel like I'm missing out on something extremely epic :D and btw just a quick question, do they have a lot of big words? I feel like a retard asking this, but I'm just a 14 year old and I don't really want to look up 1/5 words I come across in a dictionary like I did with Bram Stoker's Dracula. Thanks!