There are so many options for this out there that I am not going to be able to mention all of them. Instead I will list the ones that I have found helpful from a security context. Its mostly Python.
- Codecademy - Top code learning platform on the market
- edX | Free Online Courses by Harvard, MIT, & more
- Coursera - Build skills with courses, certificates, and degrees online from world-class universities and companies.
- W3Schools Online Web Tutorials - Best resource for learning HTML
- Codewars - CTF like challanges specifically for code building
- PowerShell vs Python Reference
- Python Tutor - Visualize Python, Java, C, C++, JavaScript, TypeScript, and Ruby code execution
- C++ Language - C++ Tutorials
- Learn Java - Free Interactive Java Tutorial
- https://github.com/EbookFoundation/free-programming-books/blob/master/books/free-programming-books.md
- https://academy.wehackpurple.com/collections - Great secure coding learning platform
- https://xapax.github.io/security/#basics_of_linux/bash_scripting/
- Advanced Bash-Scripting Guide - M. Cooper (HTML)
- Bash Guide for Beginners (2008) - M. Garrels (HTML)
- Bash Notes for Professionals - Compiled from StackOverflow documentation (PDF)
- BASH Programming (2000) - Mike G. (HTML)
- Bash Reference Manual (HTML)
- Bash tutorial - Anthony Scemama (PDF)
- BashGuide - Maarten Billemont (HTML) (PDF)
- Conquering the Command Line - Mark Bates (HTML)
- Getting Started with BASH (HTML)
- GNU Bash manual (PDF)
- Google Shell Style Guide - Paul Armstrong (HTML)
- Introduction to Bash Scripting - Bobby Iliev (Markdown, PDF)
- Introduction to the Command Line - Launch School (HTML)
- Linux Shell Scripting Tutorial - A Beginner's Handbook (2002) - Vivek G. Gite (HTML)
- Linux Shell Scripting Tutorial (LSST) v2.0 - Vivek Gite (HTML)
- Slackbook (2005) - Alan Hicks, Chris Lumens, David Cantrell and Logan Johnson (HTML, DocBook, Postscript, PDF)
- The Bash Academy - Maarten Billemont (HTML)
- The Linux Command Line - William E. Shotts, Jr. (PDF)
- Writing Shell Scripts - William E. Shotts, Jr. (HTML)
- https://wiki.sans.blue/Tools/pdfs/LinuxCLI101.pdf
- https://wiki.sans.blue/Tools/pdfs/LinuxCLI.pdf
- https://docs.quasarops.com/en/public/the-soc-analyst-scrolls/linux-commands
- A Unix Person's Guide to PowerShell - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- Creating HTML Reports in PowerShell - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- DevOps: The Ops Perspective - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- Ditch Excel: Making Historical & Trend Reports in PowerShell - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- Layman’s Guide to PowerShell 2.0 remoting (PDF)
- Learn PowerShell Core 6.0 - David das Neves, Jan-Hendrik Peters (Packt account required)
- Learn PowerShell in Y Minutes
- Mastering PowerShell v2
- PowerShell 101: The No-Nonsense Beginner’s Guide to PowerShell - Mike F. Robbins (Leanpub account or valid email requested)
- PowerShell 2.0 – One CMDLET At A Time (PDF)
- PowerShell Notes for Professionals - Compiled from StackOverflow documentation (PDF)
- PowerShell Succinctly, Syncfusion (PDF, Kindle) (email address requested, not required)
- PowerShell Tips to Write By - Adam Bertram (Leanpub account or valid email requested) (🚧 in process)
- Secrets of PowerShell Remoting - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- The Big Book of PowerShell Error Handling - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- The Big Book of PowerShell Gotchas - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- The Monad Manifesto - Annotated - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- The PowerShell + DevOps Global Summit Manual for Summiteers - The DevOps Collective, Inc. (PDF, ePub, MOBI, HTML) (Leanpub account or valid email requested)
- https://docs.quasarops.com/en/public/the-soc-analyst-scrolls/powershell
- https://docs.quasarops.com/en/public/the-soc-analyst-scrolls/one-liners
- https://xapax.github.io/security/#basics_of_windows/powershell/
- https://xapax.github.io/security/#basics_of_windows/powershell_scripting2/
- https://xapax.github.io/security/#basics_of_windows/cmd/
- https://wiki.sans.blue/Tools/pdfs/PowerShell.pdf
- https://wiki.sans.blue/Tools/pdfs/Get-WinEvent.pdf
- BeginnersGuide/NonProgrammers - Python Wiki
- https://www.learnpython.org/
- Introduction · HonKit
- Automate the Boring Stuff with Python
- comp3321 NSA Python Training Document : NSA : Free Download, Borrow, and Streaming : Internet Archive
- Cracking Codes with Python
- vinta/awesome-python: A curated list of awesome Python frameworks, libraries, software and resources
- py.CheckiO - Python coding challenges and exercises with solutions for beginners and advanced
- Invent with Python
- An Introduction to Programming in Go
- Build Web Application with Golang
- Building Web Apps with Go
- Darker Corners of Go - Rytis Bieliunas
- Effective Go
- Go 101 - @TapirLiu
- Go Bootcamp - Matt Aimonetti
- Go by Example
- Go for Javascript Developers
- How To Code in Go - Mark Bates, Cory Lanou, and Timothy J. Raymond (PDF, EPUB)
- Learn Go with Tests
- Learning Go
- Let's learn Go!
- Practical Cryptography With Go - Kyle Isom
- The Go Tutorial
- The Little Go Book - Karl Seguin (PDF, ePUB)
- Web apps in Go, the anti textbook
- ProgrammingGroundUp.pdf
- https://www.begin.re/ - Reverse Engineering for Beginners
- https://beginners.re/main.html - Understanding Assembly Language
- Reversing-Secrets-Engineering