General
- OverTheWire - tons of areas in computing to learn about with this website.
- TryHackMe - a lesson based approach to learning cybersecurity that is hands-on.
- GitHub Student Pack - free development tools for students.
- Charles ISO Mirror - ISO Mirrors for various machines that could be used.
Programming
Virtualization
Linux
Windows
Offensive Security
- HackTheBox - virtualized environments to break into various machines.
- ProvingGrounds - three hours free per day of pentesting labs (or pay).