Finding documentation.
WHAT man DOES
Shows the manual for a command.
HOW TO NAVIGATE IT
As with less: arrows, slash to search, q to quit.
WHAT THE SECTIONS MEAN
Numbers distinguishing commands, system calls, file formats and others.
WHY THAT MATTERS
The same name may appear in several sections.
WHAT THE STRUCTURE IS
Name, synopsis, description, options, examples, related pages.
WHERE TO LOOK FIRST
The synopsis, for the shape of the command, then the option you need.
WHAT --help PROVIDES
A summary, usually shorter and quicker.
WHAT apropos DOES
Searches manual descriptions by keyword.
WHEN TO USE IT
When you know what you want to do but not the command.
WHAT info PAGES ARE
A fuller format some tools use instead.
WHAT TO CHECK BEFORE TRUSTING ONLINE EXAMPLES
Whether the options exist on your system.
WHY
Options differ between distributions and versions, and copied commands fail or behave differently.
WHAT THE SAFEST APPROACH IS
Read the manual on the machine you are working on.
WHAT TO BE ESPECIALLY CAREFUL WITH
Examples containing destructive commands.
WHAT TO DO WITH ANY UNFAMILIAR COMMAND
Understand each part before running it.