It's a good idea to get to the foundations about what Joel Greenblatt talks about. Without having to dive into something dry like Security Analysis, the Intelligent Investor (though still a bit dry) basically lays out the essence of value investing.

This is another book from Joel Greenblatt which distils his method so well that this little book basically gives a single formula for investing.

That Joel Greenblatt went so far as to give out this formula freely for his readers is testament to his character.

The book is very good at condensing the complicated parts of value investing into something readable, though I think there's a lot of nuance that readers should read up on with regards the stock market before just diving into his investment formula.