You just need to configure it in one like, for ie:
var socket = io.connect('adress:port');
where addres is Your socket.io server IP or hostname, and yyyy is port on which it listens.
after that, You can get and emit events with:
socket.on('news', function (data) {
console.log(data);
socket.emit('my other event', { my: 'data' });
});
on server listen for
and thats it.
Before making chat You can try just using this example from official socket.io: link
PS dont forget to add socket.io client file source on client side! :). The whole code should look like in the example in the provided link.