|Lovecraft...at the Library!|
One of the most important and seminal writers in the history of genre literature, H.P. Lovecraft, drawing upon precursors like Poe, Chambers and Ambrose Bierce, defined the Weird fiction story as it came to be known in the golden age of the pulps--the 1920s and 30s. His so-called "Cthulhu Mythos" (which he actually referred to as "Yog-Sothothery") has gone on to influence almost every single horror author that's come along since.
If you've never read Lovecraft, you're really cheating yourself. But fear not! All of his works are in the public domain, and the fine folks at Dagonbytes are here to help out. Check out The Complete Works of H.P. Lovecraft, all online and 100% free! Beware, though: you might find out that Cthulhu isn't the nuclear-blast-immune ultimate horror that many modern works and RPGs make him out to be. In his initial appearance, they...well, I don't want to give it away. Read it for yourself and see!
Many of his works are also available in ebook format over at Feedbooks (in ePub, PDF and Kindle format)
When you're done scaring the bejeezus out of yourself...why not grab up a copy of Amazing Adventures and try to run some Lovecraft-inspired games to scare your friends just as bad?