How to stop getting internet through the prepaid card and use only my home wifi? I bought a 3G prepaid card that offers internet, but I want to stop getting Internet through the card and use WiFi to connect to his home router or certain WiFi networks of choice.

I know how to connect to WiFi. My question is how to shut off prepaid 3G internet, other than removing the card, which I find tedious.

The reason is simple, I want to use my card for phone calls only and I want to use the WiFi for Internet. Plus, my prepaid card internet is damn expensive.
To manually start and stop internet: Go to Settings -&gt; Wireless and networks -&gt; Mobile networks and disable Mobile data. This will stop internet connection through mobile network. Enable this to start internet again.

To stop it permanently:
Some application may start internet automatically, So to prevent accidental internet consumption, Create a new dummy Access Point Name in Mobile networks section and select that APN. So from next time your whenever you or any application try to connect to internet though mobile network it will try to connect though that dummy Access point and internet won't start. Internet will only work when you connect to WiFi.