Eli The Computer Guy: https://www.youtube.com/user/elithecomputerguy
Networking white hat tools: https://hakshop.com/
How to do subnetting: http://turfptax.com/wp-content/uploads/2018/05/268147-TURFPTAx-Explains-Subnetting.pdfhttp://turfptax.com/wp-content/uploads/2018/02/268147-TURFPTAx-Explains-Subnetting.pdf
Did you know that a library card in some cities grants you access to Lynda.com for free?!?!
Improve typing speed: https://typing.io/
Khan Academy: https://www.khanacademy.org/computing/computer-science/cryptography
This course is very fun and may be helpful for the puzzle on this site 😀