How do I boost wireless internet connection with a netgear router?

I have a netgear router, and I want to boost my wireless internet connection in other rooms. What can I buy or do? Is there something that plugs into the wall that can boost the signal?How do I boost wireless internet connection with a netgear router?
you can buy a wireless repeater, works like a router, only it will repeate the signal from the main router, not use it's own.