>>4
first, shut up, you fucking noob. if you actually did what
>>2 suggested, a fate you deserve would happen to you and your data.
second, depending on your desktop environment, there should be a disk free utility, I forget what KDE's is called (KDiskFree or something) but a simple search will tell you.
until you finally pull your head out of your ass and make time to do that, I will tell you linux has a simple command that does what you need, called 'df'. open a terminal and type 'df -h' and you will get the information you want. Also, if you can handle being educated, read the man page for 'du', as it is very useful for finding out how much room files and directories take on a disk.