Need Help Clearing Computer

hey everyone!

i am having trouble clearing space on my ibook G4. when i bought the ibook 2 years ago i had 40GB of storage. currently it has only 2GB of space left. so i started clearing a bunch of stuff like old videos, podcasts, and documents that i dont need anymore.

Currently i have only 5GB of storage. my itunes music only takes up 3GB, and my videos i have left take up 4GB of space. My biggest application i have is iwork which takes up 583MB.

im just curious as to what happened to all my storage space, and if anybody has had the same problem.

thanks ahead of time.