How to add songs from ipod on to itunes

You'll need a third-party app like Senuti or iPodRip. Senuti is available for Mac, not sure about iPodRip. There are a number of others, and I have a list at home that's not available to me where I'm currently posting. I would direct you to search in the forum with Zevoneer as the poster and search for the word "Senuti," but, alas, I think the search function is still disabled.

If someone doesn't beat me to it, I'll post the list after I get home.

Here you go:

Courtesy of Zevoneer

The transfer of content from other sources such as songs imported from CD is designed by default to be one way from iTunes to iPod. However there are a number of third party utilities that you can use to retrieve the music files and playlists from your iPod. You'll find that they have varying degrees of functionality and some will transfer movies, videos, photos, s and games as well. Have a look at the web pages and documentation, this is just a small selection of what's available, they are generally quite straightforward. You can also read reviews of some of them here: Wired News - Rescue Your Stranded Tunes

TuneJack Windows Only
iPod2PC Windows Only
iGadget Windows Only
iDump Windows Only
iRepo Mac and Windows
iPodRip Mac & Windows
YamiPod Mac and Windows
Music Rescue Mac & Windows
iPodCopy Mac and Windows
Senuti Mac

There is also a manual method of accessing the iPod's hard drive and copying songs back to iTunes on Windows or a Mac. The procedure is a bit involved and won't recover playlists but if you're interested it's available at this link: Two-way Street: Moving Music Off the iPod
http://www.co-bw.com/iPodmoving_musicoff.htm