Nobody mentioned MDN? (https://developer.mozilla.org/)
And this will be a great gathering of web technologies resources: http://www.webplatform.org/
I like Daily JS a lot: http://dailyjs.com
HTML5 weekly and JavaScript weekly are very useful newsletters: http://html5weekly.com/ http://javascriptweekly.com/
And the hacker newsletter too: http://www.hackernewsletter.com/