This tutorial is divided into two major sections: a Non-Programmer's Guide to JavaScript and a Programmer's Guide to JavaScript. The Non-Programmer's Guide assumes you've never coded before. It teaches more from the perspective of: These are cool things you can do. The Programmer's Guide assumes experience with some language. It tells more about how to design your own, more complex scripts.
Below are two links. One for the Non-Programmer's Guide, and one for the Programmer's Guide. Both links are run by JavaScript code, so if you don't have Netscape 2.0, you can't get to the tutorials, which is good, because without Netscape 2.0, the tutorials will look like garbage!