I have copied several CDs to my computer and then onto an iPod. Then, to free up space on the computer, I delete those files. However, iTunes later complains that the original files cannot be found. I would like to de-clutter my home and move all the music from my CDs to the iPod, throw out the CDs, and then delete those files from my computer. I don't want all that space taken up on the hard drive. How can I do this so that iTunes doesn't complain later that it can't find the original files?