Where to start?

If you don’t have basic IT knowledge, you should understand the following topics in high level:

  • Understand the importance of ethical hacking and penetration testing
  • Learn about Footprinting and information gathering
  • Acquire technical knowledge of networking basicsĀ  and protocols
  • Learn scanning networks, and how to identify network components
  • Enumeration of services
  • System-wide overview
  • Get familiar with malwares, understand their behaviour
  • Learn about Sniffing
  • What is social engineering?
  • Denial Of Service vectors
  • Sessions and their hijacking techniques
  • Known vulnerabilities and vulnerability databases
  • Web application security overview
  • Wireless networks
  • Mobile platforms, and their weak points
  • IDS, Firewalls and Honeypots
  • What is cloud computing, and how are these services being managed
  • Cryptography

If you have a basic overview of the topics mentioned above, you can start going forward for the next section. There are plenty of articles in these topics, so I can’t provide you a better collection than Google do it for you. I can only lead the way for your learning path.