how far will a 2.6ghz wireless router go?

Answer 1

Maximum for wireless is about 150 feet (or 50 meters). Reduce if you have walls, pipes, wires, trees, etc in the way. The ghz only affects the SPEED at which it talks, not the distance.

Answer 2

You mean how large an area will it cover? Depends on the area it's in. Things like the materials in walls will degrade the signal. Generally speaking I think a single access point can cover an area with a radius around 100 feet. I can see my neighbors access point in the list of available networks, but it's a really poor signal. They are just over a 100 feet away, and the signal must pass through two buildings.