NodeJS w/Express Error: Cannot GET /

You typically want to render templates like this:

app.get('/', function(req, res){
  res.render('index.ejs');
});

However you can also deliver static content – to do so use:

app.use(express.static(__dirname + '/public'));

Now everything in the /public directory of your project will be delivered as static content at the root of your site e.g. if you place default.htm in the public folder if will be available by visiting /default.htm

Take a look through the express API and Connect Static middleware docs for more info.