Books on Unix Kernels
Bach, M. J. The Design of the Unix Operating System. London: Prentice-Hall International, Inc., 1986. A classic book describing the SVR2 kernel.
Goodheart, B. and J. Cox. The Magic Garden Explained: The Internals of the Unix System V Release 4. London: Prentice-Hall International, Inc., 1994. An excellent book on the SVR4 kernel.
Leffler, S. J., M. K. McKusick, M. J. Karels, and J. S. Quarterman. The Design and Implementation of the 4.4 BSD Operating System. Addison Wesley, 1986. Perhaps the most authoritative book on the 4.4 BSD kernel.
Vahalia, U. Unix Internals: The New Frontiers. Upper Saddle River: Prentice-Hall, Inc., 1996. A valuable book that provides plenty of insights on modern Unix kernel design issues. It includes a rich bibliography.