Basic Linux Commands

hdparm
shutdown -h now

cp (copy files)
locate (fast file search)
rm -i (remove file)
rmdir (remove directory)
mv (move or rename file)
(use -i to confirm)
(use tab to complete a command or filename)

mount /mnt/cdrom
umount /mnt/cdrom

adduser username
passwd username

Ctrl-Alt-F1 - virtual console
Ctrl-Alt-F7 - X session

zip (usually "zip -r filename.zip files.*)
unzip

tar -xvf filename

To make a public environment variable use:

export varName=variableValue

(these may need to be added to .profile so they don't have to be retyped every time you log in)

echo $varName - this displays this environment variable

env - this lists all environment variables