Another reason to use the expression "climate change" rather than "global warming" is it's a far more fruitful search term. Amazon's hits on "climate change" are dramatically more useful, though Singer and Michaels do turn up. I discovered this in responding to a query this morning from a nonspecialist about what to read after "Inconvenient Truth" to learn more.
Here's my first pass at a response. Suggestions anyone?
If you have the patience, there is no better source than the IPCC itself, especially working group 1. Start with the summary for policymakers.
Somewhat easier reading is Elizabeth Kolbert's book "Field Notes from a Catastrophe".
There are a couple of other excellent pop science books I know of that give a lot of context:
Snowball Earth by Gabrielle Walker
Update: Some good suggestions in the comments. Also here's a nice Amazon list.
Plows, Plagues and Petroleum by Warren Ruddiman
All of the blogs on my blogroll are well-informed, and they span a spectrum of opinion, so that's another place to start.