I'm doing some research currently for my company on carbon offsets. I would like to just deposit a few resources here for people who may be interested in the subject.
David Suzuki's guide to carbon offsets: Fairly low-level/remedial explanation of how offsets work, what they are, and a good overall guide for someone just starting out in exploring this.
I'm simply blown away with
First Climate. It looks to be a top-notch, global organisation with a lot of experience and money behind it.