Recommendations from Portnov school students - Alex Jones.

For MAC Students: read the book "Learning Unix for OS X, 2nd Edition, Dave Taylor" if you want to know a lot about your Mac/iOS; after reading this book your will understand more than other people who has Mac; 
You will understand what is Shell, How work on computer freely without GUI just in command line (on Mac OS or Unix-like OS),  I/O Redirections | < > >> , Wild characters * ? [] {} and a lot of more. After reading this book you can work on any Linux or Unix-like OS because you will be understand shell environment.
Remember: OS X is Unix-like operating system (NOT LINUX-LIKE), OS X and iOS are based on Darwin Kernel (you can check it just type in your terminal: uname -a; and for better remember name Charles 'Darwin'); Unix was developed before Linux!
Short info: Mac OS/iOS (Darlin Kernel); Windows (Windows NT Kernel); Ubuntu, Debian, RHEL (Linux Kernel); FreeBSD (FreeBSD) & etc.
Comparison of operating system kernels: https://en.wikipedia.org/wiki/Comparison_of_operating_system_kernels

Preparation before reading the book (because Apple changed bash shell to zsh shell):
1. In run Terminal > Preferences > "Command (complete path):" /bin/bash
2. Create file in Terminal (// just comments):
	a. $ cd				// it redirect you to your home directory
	b. $ nano .profile
		and type: export BASH_SILENCE_DEPRECATION_WARNING=1	
	c. CONTROL + O 
	d. ENTER
	e. CONTROL + X

For Linux Student: if you don't have MacBook you can read: "Linux Bible 9 Christopher Negus"; after reading this book you can work on Mac or Linux (same as '4' for Mac users); or Read: "Linux Command Line and Shell Scripting Bible, Third Edition".

For Windows Students: Read "MCSA: Windows 10 Complete Study Guide" or I prefer old book: "MCTS Guide to Microsoft Windows 7, Networking, Byron Wright and Leon Plesniarski"