You'll have to connect using your Wi-Fi, there is no data plan, because you are not using the mobile network like an iPhone does. You can connect to public hotspots or other Wi-Fi networks, but they may charge you for joining the network.
If you are already using Wi-Fi at home, there are no additional charges if you connect another device to your router.
If you are any android mobile
This is what I do. Tethering? Just 3 steps.
- I just turn my Xperia X10i to Wi-Fi Hotspot.
I turn on Wi-Fi on my iPod Touch and would search for the Wi-Fi that my mobile provides.
- Connect. Enjoy.