My Ipod won't sync

So basically, I built a new computer back in November. Around January I finally was fed up with my "friend" who kept saying he was going to come over and transfer my music so I did it myself by using a USB drive. That's where my problems started. For some reason Itunes wouldn't recognize any of the music until I just dragged it into the already existing folder. So I finally at least get my music on the computer - so that was helpful. But now it won't sync anything. I have to manually drag every single song I want onto the Ipod when I have it connected via USB.

Please help me. I'm pondering Resetting the Ipod to see if that works but if it doesn't then it won't sync at all and I'm out of luck without an ipod. :-(