Another good source is
LINK which is now shipping their "green guidelines" to help get you started.
There are also books out their, such as "Green Products Guide" and others, which tell you which product and materials have achieved a green rating.
Remember, green is not as simple as pick and run, you get involved in product A versus Product B and both appear to be available to you, but at what cost??? If Product B has to ship acroos the country, or even 3-4 states, does that constitue still being green?? or is it just slightly less green than product A? It's not just manufacturing, it also reusing some materials, recycling of in-house products, energy costs to mfg...and a whole bunch more!!
Is Green right?? Sure it is, but take the time to determine what works with what, what provides what for how much, where can you use "regular" products, and where do you really want to put your "green" money!
Not so simple anymore, but it only takes time to evaluate all points!! I imagine you'll do fine!!