Model Number of iPod :
On Ipod click Menu > Settings > About (iPod touch tap Settings > General > About)
On some iPods, the model number is engraved on the metal case near the bottom.

Gigs of Hard Drive :
On Ipod click Menu > Settings > About (iPod touch tap Settings > General > About)
On some models, the drive size is engraved on the metal case near the bottom.