The Kama Sutra is an over two thousand year old text originated in India. That makes it the oldest text of its kind. The Kama Sutra is more than just a simple “sex manual”. Many of its pages deal with topics that are not related directly to sex - from how to find a wife to how to properly deal with former partners.
The parts of the Kama Sutra that are about sex also contain more than is accepted in the vanilla western world. Part two, chapters four and five are about scratching and biting. Two chapters later, part two chapter seven, is a introduction into sadism. It centers around blows and the noises the receiving partner will make in return. Also, references to anal sex are found throughout the book.
A complete free translation (without images) can be found here.