Bach, Maurice J.; Prentice-Hall; ISBN 0-13-201799-7; 470pp.; $60 (USA).
The book that got Linus started.
Tanenbaum, Andrew S.; Prentice-Hall; 1987.
Alan Cox (one of the core kernel people) likes this book. Tanenbaum designed Minix, which is the system Linus bootstrapped Linux up from.
Johnson, Michael K.
Accessible on the Web at the Linux Documentation Project page, or directly at http://www.redhat.com:8080/HyperNews/get/khg.html.
Beck, Michael & Bohme, Harold & Mirko, Dziadzka & Kunitz, Ulrich &
Magnus, Robert & Verworner, Dick; Addison Wesley; 1998;
ISBN:0-201-33143-8; 480.
See
http://heg-school.awl.com/cseng/authors/beck.m/linux/linux.html.
A guide to Linux kernel programming; covers 2.0.
McKusick, Marshall Kirk, Bostic, Keith, Karels, Michael J., and
Quarterman, John S.; Addison-Wesley; 1996; ISBN 0-201-54979-4;
608pp.
See
http://heg-school.awl.com/cseng/authors/mckusick/4.4bsd/4.4bsd.html.
The successor to a classic book on the implementation of the 4.3 BSD kernel, which influenced Linux's design (especially near sockets and networking). This book covers the 4.4BSD base of BSD/OS, FreeBSD, and NetBSD.
Dr. Dobb's Journal; Jan 1991-July 1992.