Rapid Repair is putting out their 4th Gen iPod Nano Repair guide that shows the newest remix of the Nano family piece for piece. they should also be putting up guides for the 2G Classic and the 2G Touch also. http://www.rapidrepair.com/guides/nano4g/ipodnano4grepairguide.html
You might want to check out http://www.ipod-repair-guide.com to find out about how to repair a 4th generation ipod.