Deleting Songs off your ipod
This may vary slightly depending on what type of iPod you have, but generally if you want to delete arbitrary songs on the iPod (without having to modify any playlists etc. in iTunes itself that you are syncing from), you need to have the device set to "manually manage music" on the device Summary tab. Then, you select the device from the top bar when it is connected, and open the "Music" tab, and you can select and delete songs from the list.