I find these two blogs informative and provocative:
http://makower.typepad.com/joel_makower/ (this guys runs the GreenBiz website)
http://www.marcgunther.com/ (this guy is a journalist I think)
The second one there has a really interesting post about the possibility of a carbon cap and trade program being legislated in the USA in the near future... now that would be a shocker! (Sorry, not to derail the thread).