Some of these books directly address Intrusion Detection and Prevention, while others provide insight into the subtleties of detecting malicious, anomalous, or inappropriate activity.

IDS/IPS

Snort Intrusion Detection and Prevention Toolkit

by Brian Caswell, Jay Beale, Andrew Baker

ISBN-10: 1597490997

February 2007

Intrusion Alert: An Ethical Hacking Guide to Intrusion Detection

by Ankit Fadia

ISBN-10: 1598634143

July 2007

Extrusion Detection: Security Monitoring for Internal Intrusion

by Richard Bejtlich

ISBN-10: 0321349962

November 2005

Silence on the Wire: A Field Guide to Passive Reconnaissance and Indirect Attacks

by Michal Zalewski

ISBN-10: 1593270461

April 2005v

Host Integrity Monitoring Using Osiris and Samhain

by Brian Wotring, Bruce Potter, Marcus Ranum

ISBN-10: 1597490180

May 2005

Intrusion Prevention and Active Response: Deploying Network and Host IPS

by Michael Rash, Angela D. Orebaugh, Graham Clark, Becky Pinkard, Jake Babbin

ISBN-10: 193226647X

April 2005

Hack the Stack: Using Snort and Ethereal to Master the 8 Layers of an Insecure Network

by Michael Gregg

ISBN-10: 1597491098

October 2006

Network Intrusion Detection (3rd Edition)

by Stephen Northcutt, Judy Novak

ISBN-10: 0735712654

September 2002

Intrusion Prevention and Active Response: Deploying Network and Host IPS

by Michael Rash, Angela D. Orebaugh, Graham Clark, Becky Pinkard, Jake Babbin

ISBN-10: 193226647X

April 2005

Intrusion Prevention Fundamentals

by Earl Carter, Jonathan Hogue

ISBN-10: 1587052393

January 2006

Advanced Host Intrusion Prevention with CSA

by Chad Sullivan, Jeff Asher, Paul Mauvais

ISBN-10: 1587052520

May 2006

Understanding Network Protocols

The TCP/IP Guide: A Comprehensive, Illustrated Internet Protocols Reference

by Charles Kozierok

ISBN-10: 159327047X

March 2005

Running IPv6

by Iljitsch van Beijnum

ISBN-10: 1590595270

November 2005

Understanding Malicious Code

Counter Hack Reloaded: A Step-by-Step Guide to Computer Attacks and Effective Defenses (2nd Edition)

by Edward Skoudis, Tom Liston

ISBN-10: 0131481045

January 2006

Malware: Fighting Malicious Code

by Ed Skoudis, Lenny Zeltser

ISBN-10: 0131014056

November 2003

General

The Tao of Network Security Monitoring: Beyond Intrusion Detection

by Richard Bejtlich

ISBN-10: 0321246772

July 2004

Virtual Honeypots: From Botnet Tracking to Intrusion Detection

by Niels Provos, Thorsten Holz

ISBN-10: 0321336321

July 2007

Extreme Exploits: Advanced Defenses Against Hardcore Hacks

by Victor Oppleman, Oliver Friedrichs, Brett Watson

ISBN-10: 0072259558

July 2005

Know Your Enemy

LAN Switch Security: What Hackers Know About Your Switches

by Eric Vyncke, Christopher Paggen

ISBN-10: 1587052563

September 2007

The Art of Software Security Assessment: Identifying and Preventing Software Vulnerabilities

by Mark Dowd, John McDonald, Justin Schuh

ISBN-10: 0321444426

November 2006

Hacker's Challenge 3 (Hacking Exposed)

by David Pollino, Bill Pennington, Tony Bradley, Himanshu Dwivedi

ISBN-10: 0072263040

April 2006

Penetration Tester's Open Source Toolkit

by Charl Van Der Walt, HD Moore, Roelof Temmingh, Haroon Meer, Johnny Long, Chris Hurley, James Foster

ISBN-10: 1597490210

June 2005

Network Security Assessment: Know Your Network

by Chris McNab

ISBN-10: 0596510306

November 2007

Security Warrior

by Cyrus Peikari, Anton Chuvakin

ISBN-10: 0596005458

February 2004

Hacking Exposed Cisco Networks (Hacking Exposed)

by Andrew Vladimirov, Konstantin Gavrilenko, Andrei Mikhailovsky

ISBN-10: 0072259175

December 2005

Honorable Mention

Security Metrics: Replacing Fear, Uncertainty, and Doubt

by Andrew Jaquith

ISBN-10: 0321349989

April 2007