The best JS framework I've found, and also the most widely used, is the Prototype framework. If you use Ruby on Rails the Prototype framework is integrated but you don't have to use RoR to use Prototype JS.
Download it here: prototype.js
There's some documentation here and here. There are other Prototype resources on the web to find.
There is a Prototype Lite JS with stripped down functionality also available.
Another framework, mootools, has a special FX JS that works with Prototype as well as their own framework. It includes some practical and nifty JS effects.
__________________________ Games Online ventriloquism
Thanks a lot for that site. But I already am aware of w3schools.org. Its a great site and covers almost every part of Web Designing and Development. I wanted some resources that would guide through each and every aspect of HTML, CSS and Java Script.. If you can suggest some more sites that would be a great help. Again Thank you....
_________________________ Web Design And Development
You should check out http://htmldog.com/
It's very comprehensive, and will guide you through some basic html and css concepts. After that, you just need to consult the w3schools.org reference (htmldog.com also has one, but I prefer w3schools.org...), and you're on your feet!