There's lots of good PO websites but I'll just go ahead and name a few of the obvious.
I like
LATOC because Matt does a good job of finding Peak Oil relevant news items, so I don't have to.
I get Google Alerts for "Peak Oil" and I especially like watching Peak Oil, renewable energy, and sustainability on YouTube.
I also like
http://www.kunstercast.com and
Clusterf*ck Nation,
http://www.whiskeyandgunpowder.com,
http://www.theoildrum.com, and there's many others but I'm sure other posters will name some really good sites.