www.newsnow.co.uk is easily the best website for keeping track of stories coming from all online news sources - some of the bigger blogs as well as newspapers, and from all around the world (though English-language only), and it's designed with pages for specific interests. This, for example, is NYCFC's feed:
http://www.newsnow.co.uk/h/Sport/Football/North+America/MLS/New+York+City+FC
If you register (for free) you can also set up favourites, allowing you to track multiple topics at a time. It's really useful for sampling the full range of news sources.
Otherwise, being British, I keep tabs on the BBC Football page, which is always on top of the latest news stories, but - because of their charter - pretty much only reports on stuff they can verify, so it's not filled with rumours and speculation articles as 99% of other websites are. It doesn't cover MLS in much detail (though because of Lampard and Gerrard, that's starting to change - they even did a live text coverage of the Galaxy game, which was unprecedented) - but if you want to follow a British team it really is a good source.
Can't say I go many places for discussion except team-specific forums like this one. In general, I find that any website which facilitates discussion on football but isn't aimed at one team in particular essentially is just a catalyst for arguments about whose team is hated most and very little productive discussion.