Joomla! 1.5 Development Cookbook is must-have reference for developing extensions for Joomla!(R).  I wish I had had this book a year ago, as it answers all the questions I have had about using the Joomla framework.

The book is well-organized, having the most important, need-to-know information in the first few chapters.  This is the first Joomla book I have been able to read through from front to back without skipping around.

The introduction covers using JoomlaCode.org for project management and gives a thorough explanation of version tracking.

Nothing is more important than keeping your extension secure, and 27 pages are devoted to this topic.  Examples and thorough instructions on using Joomla's filters and other functions are provided here.  Read the sample chapter from the book here:  http://joomlanyc.org/meetings-presentations/downloads/doc_download/6-sample-chapters-from-joomla-15-development-cookbook

The Session object and User object are covered in detail, as well as creating and customizing the administrator side of the component.  

I have not yet found anything in extension development that this book does not cover.  Want to include the Joomla search plugin for your component, or invoke other plugins?  It's in there.  Want to do a multilingual translation?  That's in there, too.

Using the Joomla framework makes extension development easier and faster, and this book makes it possible to quickly understand the how-to's.

This is one book that will always be by my computer.

If you wish to order the book, please note that Joomla! is a part of Packt Publishing's Packt Open Source Royalty Scheme. For every Joomla book Packt sells, they pay a royalty directly to the Joomla! Project. In addition, electronic copies of Packt's books available on www.packtpub.com.

Donna Vincent is owner of JoomSites, LLC, a web development company specializing in Joomla websites, and iTeachMe, a Joomla learning and support site.