This 432 page book written by three (3) great authors is free to download at my site.  But it would require you to register for free before you can download it.
This book will teach you about many techniques that you hardly see in Nigerians web sites and bring your awareness to the world of Asynchronous Javascript and XML (ajax).

What you will learn from this book

[list]
[li]Different methods for achieving Ajax communication and when to use each[/li]
[li]A variety of Ajax design patterns to use in specific data retrieval circumstances [/li]
[li]Techniques for using Ajax with RSS and Atom to produce a web-based news aggregator[/li]
[li]How to use JavaScript Object Notation as an alternate data transmission format for Ajax communications [/li]
[li]How to create Ajax widgets, such as a weather display and news ticker, that can be included in your web site[/li]
[/list]

Get it here http://bookazee.com.

After registration, click on the download link to download.