Remember, a lot of volatile compounds are lost when grinding. Smelling the coffee can give you a general idea of what the coffee will taste like, but you are going to loose a good portion of those to the air. This is why so many people exclaim that "they love the smell of coffee, but don't drink it." Marco has been talking about developing a "wet grinder" to capture those volatile oils which are normally lost to grinding. I will definitely second the idea of buying a grinder for yourself and promote getting a burr grinder as well. Pre ground coffee has far too much surface exposed to air, and coffee tends to be a self containing unit for only a few hours when ground, no matter the packaging. Un ground coffee is fairly good out to two weeks.
That's correct on the "Green coffee". Coffee is a small, high-moisture, seed before it is roasted. You can roast it yourself with very minimal costs. Sweetmarias.com has the best selection and, more importantly, information on this!
Best,
Phil
Denver coffee roaster