First, starting with what is coffeescript and an detailed overview blogged by krawaller, the writer has given a very good overview on coffeescript which I’m sure will help beginners. This article has referenced links that any new beginner can treat as a learning resource.
Second, coffeescript site. http://www.coffeescript.org. it has very good tutorials an online compiler and many more useful code snippets.
Third, a conversion tool js2coffee or coffee2js http://www.js2coffee.org