How can I import songs from my Ipod to my Itunes music library?

My old computer crashed along with my Itunes, when I got a new computer the Itunes software came with it. I just want to import the songs on my Ipod to my new computer without losing anything.
A few years ago my other computer had crashed and when I got a new one and added Itunes, I plugged my Ipod into the computer to import the music back to the Itunes library in my computer, but instead I lost everything on my Ipod, and in return I got the 10 or however many songs that come with Itunes when you first download the application. So I had to spend more money to buy the songs I previously had on my Ipod;
So my question is how can I import my music into Itunes without losing anything on my Ipod?
Please Please Please Help