I have listed few best hacking and penetration testing books PDF recommended by expert hackers especially for beginners. All the listed books are best based on its topic but it depends more on you what exactly you want to learn because InfoSec is a massive field.
The Hacker Playbook: Practical guide to Pentesting
The Hacker Playbook written by security professional. It is greatly informative for newbies which will guide you with practical methods, hands on examples and helpful advice from the top of the field. It is for those who have huge interest in pentesting as it doesn't require any prior knowledge of hacking. If you're a beginner and thinking of getting started then GO FOR IT!
Ethical Hacking and Penetration Testing Guide
Ethical Hacking & Penetration testing Guide written by a Pakistani prodigy hacker Rafay Baloch. It's a step-by-step guide that empowers you on how to prevent threats. Readers will acquire knowledge on how to interpret tools and will learn to perform pentesting with tools like fender Rootkit, Netcat, Fast Track Autopwn, Metasploit, Nessus, Nmap, Google Reconnaissance and Backtrack.
Black Hat Python: Python Programming for Hackers and Pentesters
Black Hat Python is one of the best book because whenever it comes to creating powerful and effective hacking tools, Python is the language of choice for most security analysts. But just how does the magic happen? You'll explore the darker side of Python's capabilities - writing network sniffers, manipulating packets, infecting virtual machines, creating stealthy trojans, and much more.
Web Application Hacker's Handbook
Web Application Hacker's Handbook focuses on finding and exploiting web apps security flaws. This practical book has been completely updated and revised to discuss the latest step-by-step techniques for attacking and defending the range of ever-evolving web applications. It is consists of 912 pages of guide and techniques on web app hacking.
Hacking Exposed Web Applications
Hacking Exposed Web App is a very informative which explores full details on the hacker's footprinting, scanning, and profiling tools, including SHODAN, Maltego, and OWASP DirBuster. You will learn advance web pentesting techniques including the most devastating methods used in today's hacks. It also covers vast section of web networking and discovering vulnerabilities.