Again, apologies to purists but Wikipedia is still a good start: http://en.wikipedia.org/wiki/Green_economy
The New Economic Foundation website is also full of amazing stuff, particularly on the issue of whether the steady state (no growth) economy is possible: http://www.neweconomics.org/
They produced the Green New Deal in 2008: http://www.neweconomics.org/projects/green-new-deal
and a good publication on the steady state economy: http://www.neweconomics.org/publications/enough-is-enough
See also Molly Scott Cato who keeps a regular flow of comment and updates in this area: http://gaianeconomics.blogspot.com/
Again any further contributions in comments.