why doesn't my ipod charge at all?

Because you haven't plugged it in?

Seriously...

If you want a more detailed answer, perhaps you could see your way to telling us what you are doing to try to charge it.

• What are you using to charge it, the USB port on your computer, an Apple wall charger or another USB charger?
• Have you tried another port on the computer?
• Does the cable look damaged?
• Have you tried another cable?
• Have you tried another charger?
• Have you tried another iPod with the same charger and cable?

- See:

iPod touch: Hardware troubleshooting

- Try another cable

- Try another charging source

- Inspect the dock connector for bend or missing contacts, foreign material, corroded contacts, broken, missing or cracked plastic.

- Make an appointment at the Genus Bar of an Apple store.

Apple Retail Store - Genius Bar