If you have wired Connection Just plug in the cable in the network port!
It'll get connected automatically!
Not so fast; it depends on the type of connection and how the router is set up. For example, I run my DSL router in bridged mode as opposed to routed mode so that I can switch between PPP connections or disconnect from the Internet when I choose. In this case, you would need to go to the Network and Sharing Centre and create a new connection using your ISP username and password.