I've gotten to the stage where I only have 3gb of my 8 gb nano left (due to deciding I wanted a whole series of the it crowd on my ipod) so I want to delete all the songs I just skip past and don't listen to anymore but I can't figure it out.

I looked at the online maual and it tells me to click on the iPod nano in the source menu. I can't find the source menu, and when I click on the picture of my iPod in itunes and it says summary I can't figure out anything else.

Please help!