drakula

I'm a newbie so i don't really understand what is going on but i was loding a bunch of music (500+) mp3's into my ibook running x.4 and it tells me now that all the music couldn't be loaded cause the disk is full. What does that mean? what did i do wrong? i was just taking a flash drive and taking it from my pc to the ibook and doing a direct flash drive to folder transfer just dragging and dropping it into the folder on my mac. Did i do something wrong? what can i do to fix it? The disc Pratition that i'm loading into is named "MaxDisk" and it only has 15gb when i go into the disk utility it says i used all 15 but the hard drive is a 40 gb what am i doing wrong? Please help.