Boehm, Barry W. Software Engineering Economics. Englewood Cliffs, NJ: Prentice-Hall, Inc., 1981. Chapter 21 describes a seven-step approach to estimating software projects.
Cooper, Robert G. Winning at New Products: Accelerating the Process from Idea to Launch. New York, NY: Perseus Books Group, 2001. Cooper is the father of stage-gate processes. This book describes how to develop your own stage-gate process.
McGarry, John, et al. Practical Software Measurement: Objective Information for Decision Makers, Boston, MA: Addison-Wesley, 2002. Section 5.1 discusses considerations to include in an estimation procedure.
NASA SEL. Manager's Handbook for Software Development, Revision 1. Document number SEL-84-101. Greenbelt, MD: Goddard Space Flight Center, NASA, 1990. This document describes the NASA SEL's estimation approach in more detail.