The ones Bear and William posted are good. But I use this one (
http://www.hltv.org/?ref=logo) for Twitch links / lineups and whatnot. You can also go to the match overview on csgolounge and I think they have a link or two buuut they won't pop up until like a bit before the match starts. You didn't mention it; but if you're interested in betting, that also can be done on bear's link. As for tournaments right now, I don't think there's any big big ones (could be wrong on that and I'm sure someone will correct me if I am), but there's a bunch of minor tournaments / skirmishes or whatever constantly going on that are worth the watch (such as this Titan vs HR game
http://www.hltv.org/match/2292922-titan-hellraisers-sltv-starseries-xi). Hope that was what you were looking for, sorry if I went a bit overboard :b