Qualys offers QualysGuard® PCI Compliance (PC) provides businesses, online merchants and Member Service Providers the easiest, most cost-effective and highly-automated way to achieve compliance with the Payment Card Industry Data Security Standard. Registering with Qualys for their free book offer provides you with these excellent references.

PCI Compliance for Dummies
Complying with the PCI Data Security Standard may seem like a daunting task for merchants. This book is a quick guide to understanding how to protect card holder data and comply with the requirements of PCI - from surveying the standard's requirements to detailing steps for verifying compliance.

Vulnerability Management for Dummies
As a business owner, or someone responsible for network security within your organization, you need to understand how to prevent attacks and eliminate network weaknesses that leave your business exposed and at risk.
Vulnerability Management for Dummies arms you with the facts and shows you how to implement a successful Vulnerability Management program. Whether your network consists of just a handful of computers or thousands of servers distributed around the world, this 5-part book will help.