To development games with Cocos2d-Html5, there are some prerequisites that are nice to have, and some that are almost mandatory.
The only thing that�’s mandatory for developing Cocos2d-Html5 game is some degree of programming experience. You should have an understanding of programming concepts like loops, functions, classes, and so on. If you have written a program before, preferably using a scripting language, you should be fine.
So you do have programming experience, but maybe you� have never written anything in JavaScript.
Because on top of Cocos2d-Html5 is an set of JS APIs, it definitely helps to know JavaScript basics. You can found some basic info about JavaScript on Wikipedia. The best tutorial of JavaScript programming can be found on W3schools.
The Cocos2d-html5 way of object inheritance is comes from John Resig's javascript Inheritance, you'd better to learn about it.