The Zend Developer Zone has posted a book review of an Packt book, "Building Websites with Joomla! 1.5" (by Hagen Graf - the book, not the review):

The book is a tutorial guide to Joomla! 1.5 and was already written and published during the development of Joomla! 1.5. This is the final version and it aims for "web developers, designers, webmasters, content editors and marketing professionals" and is suitable for anyone starting out with Joomla! 1.5, for people who upgrade to Joomla 1.5 and for those who just want a good printed guide/manual at hand.

The review steps through the chapters, highlighting points of interest and the wrapup uses terms like "great instructional value", "very passionate about Joomla!" and the fact that the only thing the reviewer sees missing of a chapter about security.