I found the Skeptical Science site a while back when looking for backup in an email argument about global warming.
This latest post, I think, sets out the picture quite clearly.
The thing I like best about the way the articles on that site are written is the way citations are given, so you can look up the scientific papers yourself, and see what the experts in the field are writing.
I found it particularly interesting to read the article about how much heat the oceans are storing - it really shows the extent of the problem, and explains a lot why you'd see stories like this one, stating that the Arctic could be almost ice-free in summer within a few years.
The way most comments use a similar style (including citations to back up points) is quite refreshing! Certainly a much higher standard of commentary than you see on many sites (although the occasional "I don't believe you, just because!" comment sneaks in...)