I want to transer my music from my ipod to itunes and my new computer

iPods are neither designed nor suitable as data storage devices and are far too liable to loss, theft or damage to be used as the only place you have your music. You should manage your music in iTunes, and create/maintain a regular backup of it.

Ideally you should copy your iTunes library from the computer previously used to sync music to your iPod - see How to move your iTunes library to a new computer.

Otherwise, see turingtest2's user tip on Recover your iTunes library from your iPod or iOS device for various methods and tools that can be used to recover media from your iPod and restore it to your library. There's a link at the end to an iLounge article which describes how to recover music and most metadata using Windows Explorer/File Explorer (Windows) or Finder (Mac) - requires no additional software (free or otherwise), though even though this allows all your music to be retrieved it doesn't rescue any playlists, playcounts, or ratings from your iPod and may result in some albums without artwork.