Welcome to the Apple Support Communities. It sounds like the easiest way to take care of iTunes library is to create a new library. The following article will assist with that process.
After you have created a new library, the next step would be to add the media to the library.
One last thing is to make sure that the library stays organized. This option is in the preferences in iTunes.
- Open iTunes.
- Choose Edit > Preferences.
- Click the Advanced tab in the Preferences window.
- Select the "Keep iTunes Media folder organized" checkbox.
- Click OK.