Book by Douglas Crockford: JavaScript: The Good Parts.

Succint description of a subset of Javascript and practices that allows for a safe usage of the language, in order to keep projects maintainable. Some parts to really avoid are also listed.

My favorite item is on object construction: using a standard functions instead of constructors (quite like Item 1 of Effective Java), giving a more flexible aproach to create objects, removing the risk of forgetting the new keyword, and allowing true private fields thanks to functional scope.