Listmania!
IT Security: Reference and Casual Reading
Secrets and Lies: Digital Security in a Networked WorldSecrets and Lies: Digital Security in a Networked World by Bruce Schneier
Buy new: £8.36 / Used from: £5.00
Compulsory reading for anyone in IT, and not just the security side of things.
Beyond Fear: Thinking Sensibly About Security in an Uncertain WorldBeyond Fear: Thinking Sensibly About Security in an Uncertain World by Bruce Schneier
Buy new: £14.39 / Used from: £7.45
Again an essential read from Schneider.
Mastering FreeBSD and OpenBSD SecurityMastering FreeBSD and OpenBSD Security by Yanek Korff
Buy new: £26.95 / Used from: £19.93
FreeBSD is a damn good OS and secure oob, but anybody running it in a secure environment should read this book.
BSD Hacks: 100 Industrial Tip & ToolsBSD Hacks: 100 Industrial Tip & Tools by Dru Lavigne
Buy new: £16.14 / Used from: £10.00
... and this one. Though it is more related to admin tasks.... No matter how much you think you know FreeBSD some of these tips will be essential.
Information Warfare and SecurityInformation Warfare and Security by Dorothy E. Denning
Buy new: £27.19 / Used from: £15.49
An old book but still very relevant.
Crypto: Secrecy and Privacy in the New Cold War (Penguin Press Science)Crypto: Secrecy and Privacy in the New Cold War (Penguin Press Science) by Steven Levy
Buy used from: £0.45
Fascinating insight into the early roots of cryptography (and how the brits actually invented asymmetric encryption first).
TCP/IP Illustrated: Protocols v. 1: The Protocols (APC)TCP/IP Illustrated: Protocols v. 1: The Protocols (APC) by W. Richard Stevens
Buy new: £28.96 / Used from: £23.00
The bible of networking.
Masters of Deception: the Gang That Ruled CyberspaceMasters of Deception: the Gang That Ruled Cyberspace by Michele Slatalla
Buy new: £6.46 / Used from: £1.89
An entertaining read.
SSH, The Secure Shell: The Definitive GuideSSH, The Secure Shell: The Definitive Guide by Daniel Barrett
Buy new: £17.23 / Used from: £21.30
Any network engineer should know ssh inside out.
The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer EspionageThe Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage by Cliff Stoll
Buy new: £7.63 / Used from: £4.02
A great page turner.
CISSP All-in-One Exam Guide (All-in-one S.)CISSP All-in-One Exam Guide (All-in-one S.) by Shon Harris
Buy used from: £5.00
A huge book but worth getting through.
DNS and BINDDNS and BIND by Cricket Liu
Buy new: £22.05 / Used from: £21.74
If you have anything to do with DNS, read this book.
Mastering Regular Expressions (Nutshell Handbooks)Mastering Regular Expressions (Nutshell Handbooks) by Jeffrey E. F. Friedl
Buy used from: £21.73
Once you have them cracked they make life so much easier.
Applied Cryptography: Protocols, Algorithms and Source Code in CApplied Cryptography: Protocols, Algorithms and Source Code in C by Bruce Schneier
Buy new: £24.67 / Used from: £17.00
Heavy going if you don't have a maths degree, but worth sticking with.
Hacking Exposed 5th Edition: Network Security Secrets & Solutions: Network Security Secrets and SolutionsHacking Exposed 5th Edition: Network Security Secrets & Solutions: Network Security Secrets and Solutions by Stuart Mcclure
Buy new: £25.64 / Used from: £6.00
Each book I have read in this series has been very informative.
Boo Hoo: A Dot Com StoryBoo Hoo: A Dot Com Story by Ernst Malmsten
Buy new: £6.74 / Used from: £0.01
If you are involved in IT and business you should read how NOT to do things.