The book is structured as: An overview of the architecture of the application and database, how it all fits together, A module development tutorial, showing the essential steps for hooking your module into the SugarCRM infrastructure, A section of common customizations that can be performed against the codebase The book is for PHP developers working with SugarCRM, who want to extend its capabilities. Readers should have a basic knowledge of SugarCRM as the book does not cover installation and usage of SugarCRM. This can be gained from Implementing SugarCRM.