How do I move songs from one playlist to another in itunes?

My library list pretty much matches my shared file folder on my hard drive but when I plug in my ipod, it doesn't upload all of my songs the library. Why is that?

Also, I have what is called an Administrator's list, which is about 50 songs less thatn my Library. I am so confused.

When I download a song on limewire, it gets saved to my shared folder. Then I'll import that folder into itunes. But there is a library folder and an administrator folder. They differ in song lists. (It did this automatically) The Library has about 987 songs and the administrator file has about 927.

Then the ipod list only uploads 887 songs. I don't know how to correct this.

I know it is something easy but I am confused. Please