[JonK]

You'll lose about 15 to 20% of the weight of the green bean on roasting, depending on the bean and the degree of roast. If you just want to experiment without a major investment, try using your hot air pop corn popper. Don't put in more than about a half cup of beans and listen for the first and second cracks (a popping sound). You'll want to start checking for degree of doneness shortly after the second crack (or earlier if you prefer something lighter than a city roast). You'll want to cool the beans quickly, say by tossing around in a sieve. Expect to smoke up the kitchen a bit.

I rely on a local roaster who promises that his beans are no more than 48 hours out of the roaster. Despite Alton Brown's warning to not store roasted beans in the frig (it has to do with condensation of moisture), my own blinded experiment wth beans stored at room temp vs. in the refrigerator suggested that cooler is indeed better. I could tell no difference between refrigerated beans and those stored in the freezer, but I may not have run the experiment long enough.