I wrote a Short Cut for O'Reilly that just came out called Unobtrusive Ajax. You can buy it online for just $9.99.

It's a 57-page PDF that goes into depth on using JavaScript and Ajax unobtrusively, an extension of my Unobtrusive Ajax presentation. From the description:

Unobtrusive Ajax is about making web applications that work for everyone all the time, even if you have JavaScript turned off, or you're using a mobile phone or a screen reader, or however you happen to be using the Web. It's about the separation of behavior (JavaScript), content (HTML), and presentation (CSS).

This short cut will focus on the practical benefits of using Ajax and JavaScript unobtrusively and show you that unobtrusive web development and progressive enhancement benefit both web developers and users of the Web. You'll get to see many simple examples of building web interfaces that are unobtrusive. You'll quickly see that it is actually very easy to make web applications that everyone can use.

When you're finished reading this short cut, you will be able to convince anyone why developing unobtrusively is the best way to build a site with JavaScript and Ajax.

I'd like to give a big thanks to the king of Unobtrusive JavaScript, Christian Heilmann, for giving me a great technical review.

If you're into this sort of thing, or even if you're not but wondering if you should be, I recommend you check it out.