You really need to read the link he gave you.
Also, it would be highly advisable to understand basic networking terminology, otherwise you will get mixed up as to which device is which. You seem to have your terms the wrong way around. You can't connect your "computers and all wireless devices" to a router. A router routes traffic from one network to another, it doesn't connect many devices together, that is a switch.
Some of these devices are commonly combined into a single box, which can confuse matters slightly. For instance, it is common to combine an ADSL router with a switch, so that it routes traffic between the public Internet and your internal network (a router function), AND provides, say, 4 switch ports to connect multiple devices to (the switching function). ADSL broadband devices are usually routers, whereas cable broadband devices are commonly only bridge devices, and need something else to provide the standalone routing function (a LMCE core can do this for you).
If the device you are describing above is a wireless AP, then I would guess it also has a built in switch functionality and 4 switch ports. This means it combines the functions of an AP and switch, but probably not a router as well. First step, find out exactly what equipment you do have. Second, read that article on Network Setup and follow it.