/bin : Used to hold executable files, found all over the file system.
/sbin: Used to hold the supervisor’s (root) executable files.
/boot: Boot up files like the kernel are stored here.
/dev : This folder holds the device driver files. They are used to represent physical items, e.g. /dev/tty1 = communication port 1.
/etc : Used to store most of the configuration files for Linux.
/home : Stores all the user home directories.
/lib : Stores the libraries/run times for programs.
/mnt : Unlike in Windows where c:\ represents a drive, in Linux the different drives are stored in /mnt and act like a directory.
/proc : Holds most of the processes happening in the Linux system.
/root : The supervisor’s (root) home directory files.
/usr : Stores user based files.
/var : Holds constantly changing files like print spools.
/tmp : Temporary file folder.

Unlike in Windows, you must manually mount the cdrom drive unless you have a program to do it for you. In KDE, if you click on the cdrom icon you can mount the cdrom automatically. To mount a cdrom drive use: mount /dev/cdrom or mount /mnt/cdrom. To unmount it use: unmount /mnt/cdrom. Try as you might, you won’t be able to get the cdrom out of the drive while it is mounted. New versions of Linux have supermount which mount and unmount the cdrom drive for you (like in Windows).