Below are several places to go to find information / training materials related to JavaScript and jQuery:

Information:
  1. http://jquerytools.org/
  2. http://www.ecmascript.org/
  3. https://developer.mozilla.org/en-US/docs/JavaScript

Training:
  1. http://www.w3schools.com/js/default.asp
  2. http://jquery.com/
Please always remember to keep a backup of your original Script locally (in notepad / text editor) before making changes or edits.