In general, JavaScript is a pretty straightforward language where anyone can learn the basics within hours.
And, like any other language, some common mistakes and bad practices -which can be avoided easily- exist.
JavaScript Garden is a growing collection of documentation about the most quirky parts of the JavaScript programming language. It gives advice to avoid common mistakes, subtle bugs, as well as performance issues and bad practices that non-expert JavaScript programmers may encounter on their endeavours into the depths of the language.
The project is also handy as it is sometimes hard to debug JavaScript code (specially for beginners) because of unfriendly errors in some situations.
To sum up, bookmarking the project and referring to its related category in case of a hard-to-fix error would be good idea.
Download Javascrit Guide: Javascript Garden
Website: http://bonsaiden.github.com/JavaScript-Garden/
Download: https://github.com/BonsaiDen/JavaScript-Garden