Python:
Python_Tutorial.pdf
Scipy_Lecture_Notes.pdf (Debugging, Profiling and interfacing with C)
Learning_Python.pdf
Programming_Python.pdf
Modeling_and_Simulation_with_Python.pdf
Python_for_Unix_and_Linux_System_Administration.pdf
Introduction_to_Scientific_Computing_in_Python.pdf
How_Think_Like_Computer_Scientist-Learning_Python.pdf
Functional_Python_Programming.pdf
Automate_the_boring_stuff_with_Python.pdf
Python_Cookbook.pdf
Python_GUI_Programming_Cookbook.pdf
Programming_in_Python3.pdf (9.Debugging, Testing, and Profiling)
Programming_Python.pdf (GUI, Systems programming)
Fluent_Python.pdf
Unit_testing_with_pytest_and_nose.pdf
Python4-Advanced_Python.pdf

Website:
The Python Tutorial
https://docs.python.org/3/tutorial/index.html
Library Refernce (keep this under your pillow)
https://docs.python.org/3/library/index.html
Language Reference (descruves syntax and language elements)
https://docs.python.org/3/reference/index.html
Python Setup and Usage (how to use Python on different platforms)
https://docs.python.org/3/using/index.html
Python HOWTOs (in-depth documents on specific topics)
https://dpcs.python.org/3/howto/index.html
Installing Python Modules (installing from the Python Package index & other sources)
https://docs.python.org/3/installing/index.html
Distributing Python Modules (publishing modules for installation by others)
https://docs.python.org/3/distributing/index.html
Extending and Embedding (tutorial for C/C++ programmers)
https://docs.python.org/3/extending/index.html
Python/C API (reference for C/C++ programmers)
https://docs.python.org/3/c-api/index.html
Python 3.8.0 documentation (documentation for Python 3.8.0)
https://docs.python.org/3/
Full Stack Python (Web Development)
https://www.fullstackpython.com/
Google's Python Class
https://developers.google.com/edu/python/
Corey Schafer - coreyms.com

ViTextEditing:
vi_reference.pdf
vi_and_vim_Editors.pdf 

R:
Hands_On_Programming_with_R.pdf
Practical_Data_Science_with_R.pdf
Introduction_to_Data_Science_with_R (Video) - code at github

Ploting:
ggplot2.pdf
ggplot for Python (find)

Google's Coding Competitions 
https://codingcompetitions.withgoogle.com/

Linux:
Debian_Reference.pdf
Ubuntu_Linux_Toolbox.pdf # Chap: 15 Virtual Machines
Practical_LPIC-1.pdf
Practical_LPIC-3.pdf
Essentials_System_Administration-LFS201.pdf
Python_for_Unix_and_Linux_System_Administration.pdf
linux_programming_unleash.pdf
The_Linux_System_Administrators_Guide.pdf
Linux_Network_Administrators_Guide.pdf
https://lwn.net/

Shell Scripting:
Linux_Shell_Scripting_with_Bash.pdf

SQL:
Introduction_to_SQL.pdf
Learning_SQL.pdf
Effective_SQL.pdf
MYSQL_in_a_nutshell.pdf
MySQL Knowledge base - http://www.mysql.com/network/knowledgebase/html

DataScience:
Python_Data_Science_Handbook.pdf (4.Visualization with Matplotlib)
Data_Science_Command_Line.pdf
Data_Science_from_Scratch.pdf (23.Databases and SQL)
Python_for_Data_Analysis.pdf
Mastering_Python_for_Data_Science.pdf
Introduction_to_Machine_Learning_with_Python.pdf
Modeling_with_Data-Tools_and_Techniques_for_Scientific_Computing.pdf 

Natural Language Processing:
Natural_Language_Processing_in_Action.pdf
Python_Text_Processing_with_NLTK-Cookbook.pdf

Haskell:
https://wiki.haskell.org/Books
Learn_You_a_Haskell_for_Great_Good.pdf
The_Haskell_Road_to_Logic_Math_and_Programming.pdf
Practical_Haskell.pdf

Mathematics:
Mathematical_Methods_for_Physicists-A_Concise_Introduction.pdf
Modeling_with_Data_Ben_Klemens.pdf

HTML Color codes:
https://htmlcolors.com
https://web.mit.edu/rsi/www/pdfs/beamer-tutorial.pdf

Arch Linux:
https://wiki.archlinux.org/index.php/Main_page
https://wiki.archlinux.org/index.php/Arch_compared_to_other_distributions

Gentoo Linux amd64 Handbook: Installing Gentoo
https://wiki.gentoo.org/wiki/Handbook:AMD64/Full/Installation
https://wiki.gentoo.org/wiki/Main_Page

Slackware Linux:
https://slackwiki.com/Minimal_System

Programming for Physics and Astronomy:
http://prancer.physics.louisville.edu/astrowiki/index.php/Programming_for_Physics_
and_Astronomy

xkcd - [A webcomic of romance, sarcasm, math, and language.] https://xkcd.com/
