It might seem obvious, but the first prerequisite to setting up a Wi-Fi access pointthat will let the computers on your network connect to the Internetis a working Internet connection. This is true for the obvious reason: You can't connect to the Internet without a connection. But a couple of other points are involved as well. You'll need to know some of the settings to put into the access point so that it can connect to your Internet service provider (ISP).
One of the easiest ways to find these settings is to read them off your Internet-connected computer. (See the following section, "Collect Your Settings," for details.)
Many cable and DSL service providers might state as their official policy that they only support one computer connected to their service. But service providers have come to realize that a great many people connect networks, including wireless networks, to the Internet. If you have a network attached to the service, they won't help you configure the networkat least not for freebut they will help you with your Internet connection. To do this, quite likely they will ask you to connect a single computer to the modem attached to your broadband Internet connection.
All this means is that, if at all possible, you should have a computer up and connected by wire to the Internet first to collect the Internet settings, and you should also make sure that the connection is working properly.