"Lady Chatterley's Lover" was written in the early 1920s by D.H. Lawrence. Because of its then explicit sexual content, it was banned for many years, and only published after a lengthy court battle.
While Lady C.s exploits may seem tame in the era of "Clan of the Cave Bear", please remember that "Gone with the Wind", written ten years afterwards, refers to sex as "the marriage act" and even that was considered risque.
Rather than read this excellent novel for the shock value of the sex, I would suggest reading it for its touching story, its absorbing characters and Lawrence's elegant portrayal of the educated classes between the wars.
For modern readers, the 'shocking' part of the novel is in the use of the word 'cunt'. Once upon a time, this word simply meant 'vagina' and Lawrence uses it to mean 'female genital area' and, interestingly, 'making love'. Its use is meant to imply that Mellors is lower-class. He uses 'cunt', a pre-Norman English word rather than a Latin word, like 'vagina', or a polite euphemism.