Wifi setup with Laptop and dongle for use with iPod touch?

I have been using a laptop with 3g internet (dongle) and i wanted to setup a wifi so i could use it on my iPod touch. I got a wireless router and its working and my ipod picks it up and connects to it. But the problem is that the only internet i got if the dongle and i dont know how to make my router so it uses the dongle internet. My wifi network currently doesn't have internet. I need to know how to set it up so my 3g dongle internet is being used with my router.. ?? Thanks.