Node JS - HTML Paths

Look at this:

app.get('/', function(req, res){
    res.sendFile(__dirname + '/index.html');
});

You have told Node "When the browser asks for / give it index.html".

What happens when the browser asks for someScript.js?

You haven't told Node what to do then.

(You'll probably want to find a library for serving up static files rather than explicitly handling each one individually).