JavaScript is unlike most other languages. While it is Object Oriented, it is weakly typed. This provides much greater flexibility, but at the same time, limits itself.
Keep a few sites in your pocket:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide
http://javascript.crockford.com/
http://www.addedbytes.com/cheat-sheets/javascript-cheat-sheet/
One last thing:
Be aware of Douglas Crockford. Read his books. Read anything you can find with his name on it.
