There are tons of programs that will do this automatically for you. They are not free. You may try this iPod transfer software to take all your music off iPod, my friends recommend it to me, it's not free, but it's easy to use and works pretty well for me, I think it well worth the money. If you are interested in it, here it is:
http://www.bigasoft.com/ipod-transfer.html
WARNING
Free try before you buy
Not works for music with DRM