Cleaning out hard drive.

[XRIMO]

Okay, so for the past couple weeks I keep getting a warning that I'm low on disk space. So I click on the icon and it cleans up some files and restores a bit of memory, however, each time I do this it restores less and less. Now its at the point that it doesn't seem to make a difference. I can't figure out what is eating up all my disk space since I don't download anything and I haven't been using my internet all that much. Is there any tips about what I can do to free up some space?