The following books and references can provide you with a deeper look at Capability Maturity Model Integration:
CMMI, Guidelines for Process Integration and Product Improvement by Mary Beth Chrissis et al. (Addison-Wesley Professional)
This is the official CMMI specification, published by the Software Engineering Institute through Addison-Wesley. The book is organized into three main parts. Part 1 describes the model's approach to process improvement and presents the methods by which CMMI can be implemented in an organization. Part 2 contains full descriptions of each of the 22 Process Areas in CMMI. Part 3 contains an extended glossary and other reference material.
CMMI Distilled by Dennis M. Ahern et al. (Addison-Wesley Professional)
This book offers tips and techniques for implementing CMMI, whether the organization is starting with a "fresh" process program or is migrating from an established one into CMMI. There is a lot of advice here on how the CMMI team might be structured and what responsibilities it should undertake. And the authors offer their own lessons on how to make implementations the most effective. The book also provides descriptions and guidance concerning SCAMPI, the CMMI appraisal process.
Real Process Improvement Using the CMMI by Michael West (Auerbach)
This book presents what might be called a critical look at implementing CMMI. The author focuses on the practical application of this framework and leaves theory for other works. I sat with the author's wife, Jitka, at an SEI training session, and she stressed the value of this "practical" approach. The book works to establish real-world expectations of how CMMI can benefit an organization and provides practical tips on realizing the full value from an implementation.
Software Process Improvement with CMM
by Joseph Raynus (Digital)
This work is addressed to project managers and management looking to get a practical understanding of process improvement using the CMM. The CMM is an earlier version (now sunset) of CMMI, but the book's focus on implementing CMMI processes across the phases of a project life cycle is very well done and thorough, and the advice still remains true for CMMI. So it's still worth a look.
Interpreting the CMMI: A Process Improvement Approach by Margaret Kulpa and Kent A. Johnson (Auerbach)
This significant book lays out recommendations and advice for using CMMI as a foundation for organizational process improvement. The book presents the details of what the specification recommends in terms of goals and practices. But its real focus is on techniques for interpreting the model so that it best fits with the culture of the organization and also addresses the core process improvement needs within the organization.
Practical Insight into CMMI by Tim Kasse (Artech House Computing Library)
This work presents a general picture of the kinds of activities in software and systems engineering shops that can benefit from the implementation of CMMI Process Areas and practices. The book describes the roles and responsibilities that are required to advance the use of CMMI and offers advice to project managers, technical managers, and senior management. Available as a digital download.