Seeing as how it's getting animated, I might as well make a thread for the novels....
Another is a school horror story by Ayatsuji Yukito and published by Kadokawa Bunko.
Story spans two volumes.
Novel site:
http://www.another-anime.jp/goods/#booksInfo
Synopsis:
Finished the first volume and it's really good so far. The kind that keeps you turning the pages to find out what happens next.