Prentice Hall have published Joomla 1.5 - A User's Guide by Barrie M. North.

The book takes readers step-by-step through developing a successful website powered by Joomla.

It gives a general overview of CMS management and teaches key concepts regarding content organization, editing, and templates. It also examines some more general topics such as how Search Engine Optimization (SEO) can be maximized with Joomla and what resources are available in the Joomla web community. Readers are not expected to know any PHP, CSS, etc so the book is suitable for novice users.