The Yellow Wallpaper - Charlotte Perkins Gilman

This is a short book - more like a long short story, I guess - that packs a wallop! I really enjoyed it. Originally published in 1892, it's available in book form, although I read it through Project Gutenberg. I'd actually like to see a version that has commentary and historical info, and info about the author, etc. after having read this - more inspiration for research! I can't say much about it without running into a spoiler, so I'll just say this is highly recommended.