I don't think there is any possible way that your iPod or computer could be damaged using this method, but if anything does become damaged or broken I cannot be held responsible. Use this information at your own risk. Never disconnect your iPod when transferring or synchronizing!
Step 1: Plug in that iPod
Step 2: Get the music to your computer.
Find the Music folder, it's inside iPod_Control
Drag and drop the Music folder to your desktop. Wait for it to transfer. It may take awhile, make sure you have enough disk space!
Once it's done copying, right click the folder, go to properties, and make sure 'Hidden' is unchecked.
Congratulations the music is now on your PC! Next we're going to get it into iTunes.
Step 3: Import your music into iTunes.
Now, there are two paths.
If your iTunes is set to automatically copy and sort music for you [recommended]:
1. Drag and Drop the Music folder from your desktop into iTunes and wait for it to copy. Make sure you have enough disk space before doing this because your will eat up 2x the disk space temporarily!
2. Delete the Music folder off the desktop. It's no longer needed.
If your iTunes is set so that the user copies and sorts music:
1. Move the Music folder into your preferred directory.
2. Drag and drop the new music into your iTunes.