http://www.asciitable.com/
ASCII stands for American Standard Code for Information Interchange. Computers can only understand numbers, so an ASCII code is the numerical representation of a character such as ‘a’ or ‘@’ or an action of some sort.

https://stackoverflow.com/   Stackoverflow is a privately owned website, featuring questions about coding and answers from professionals.

www.github.com
Github is a free site that offers access to open-source codes and wikis for all their projects.

http://www.codecademy.com 
Helpful for practicing or learning new coding languages, and it’s free!

https://ocw.mit.edu/courses/#electrical-engineering-and-computer-science Offers free access to MIT’s computer science manuals and books, and provides help with coding problems.

https://cse.unl.edu/faq
Index of frequently asked questions regarding CSE accounts, email, printing, networking, and more.