Click 'Get a Quote' and you will see a random quote selected from a randomly chosen book.
Guess which book the quote came from by selecting one of the books in the 'Pick One..." drop down list
That's all there is to it. You can choose different sets of books by clicking the 'change books" option.
The Facebook share button will include the sequence of quotes you see in the show quotes option, presenting them as a sequence of quotes for the other person to guess. When the recipient gets to the end of the sequence, they will be told how their score compares with yours
You can always skip a quote by hitting 'Get a Quote' without attempting a guess (pretty wimpy). You can reset your current session by either the 'return to game and reset' selection on the options pop-up or by selecting another book. Have fun!