The new ipod nano 5th generation video to computer and DVD to ipod?

hey well i got my ipod nano 5th generation the one with the video camera.
i have heaps of videos that i have taken with it, but i dont no how to get those videos and put them in my computer. they wont show in my itunes wen i plug it in i dont get it, how do i get those videos and put them on my comp.

I also want to upload a home movie from a DVD to my PC and put it on my IPOD.

Can anyone please walk me through the steps. I have no clue what I am doing!