To create AJAX applications you must have:
The material in this guide assumes that you have these skills already.
You do not need any XML or XSLT skills.
If you do not have basic JavaScript or HTML/DHTML skills you should build them up first using simple examples. There are many excellent books and websites that can help you acquire these basic skills. For example http://www.w3schools.com/.
If you already have these skills and wish to apply them in the Framework-AJAX context, the best place to start is with the AJAX Exercises in this guide.