Cyber Security

Links to start learning about "CTF-style" cybersecurity events:

CTF events that are going on or will be starting soon:
Kali Linux
This is the OS we used pre-loaded with tools for cyber security.  It can be run off of a bootable flash drive or ran in a virtual machine.

One of many tutorials available just by searching "tutorials Kali Linux" or "getting started with Kali Linux."  
Metasploitable is a weakened OS with many exploits.  It's to be penetrated using Metasploit, which is included in Kali Linux.

Damn Vulnerable Web Application (DVWA)
Damn Vulnerable Web App is a PHP/MySQL web application that is damn vulnerable. 

Tools for looking up information about a web URL

Database for vulnerabilities.

Free, open-source packet manager.  Used to find out what traffic is on the network.  Included in Kali Linux.

In-depth security new and investigation

Network security sub-Reddit

The Open Web Application Security Project (OWASP) is a worldwide not-for-profit charitable organization focused on improving the security of software.

Text-sharing website