ShellsTopic
Also see a dedicated wiki for shells:
sh/
ShellNotes
.
BashStuff
ZshStuff
UsefulConsoleStuff
XonshNotes
UsefulShortBashScripts
This is worth a read regarding csh:
https://www-uxsup.csx.cam.ac.uk/misc/csh.html
LinuxNotes
Ubuntu2004LTS