The #1 book is "Design Patterns: Elements of Reusable Object-Oriented Software" by Gamma/ Helm / Johnson / Vlissides. It's about imperative programming though,

The #1 book is "Design Patterns: Elements of Reusable Object-Oriented Software" by Gamma/ Helm / Johnson / Vlissides. It's about imperative programming though, functional/hybrid languages have other design patterns(but "Design Patterns" is #1 anyway). + Free Book "The Architecture of Open Source Applications" : http://hackershelf.com/book/54/the-architecture-of-open-source-applications/ http://hackershelf.com/book/54/the-architecture-of-open-sour...