Here's a nice article from K. Scott Allen about JavaScript and the Object Oriented side of it.

To summarize the article let's quote the man:

"This article presented three key pieces of knowledge:
  1. Every JavaScript object is a dictionary.
  2. Every JavaScript function is an object.
  3. Every JavaScript object references a prototype object.
Those are three fundamental facts about JavaScript that also make JavaScript different from mainstream CLR languages like C# and VB.NET. Embracing and internalizing these differences will put you ahead of the game in understanding modern JavaScript frameworks, toolkits, and libraries."

Are you convinced yet?