I've been roasting green coffee beans for a few years now, and finally I think the time has come to let everyone in on the secret: it really is very easy. It's also a lot cheaper than buying roasted beans, and obviously they are so fresh!
I've been ordering my beans since 2009 over the 'net from the good folks at Coffee Snobs and have always found them to be on time and good value. Previous to that, I was visiting Withams, give them a go if you are in the Sydney area!
Coffee Snobs operate a "bean bay", where, once a month, they fill the site with new specialty coffee beans. That being said, whilst some sell out very quickly, I always find my beloved South American and Indonesian beans in stock, no matter what.
I use a popcorn popper to roast my coffee beans. I currently use a Sunbeam "Cornelius". Just so you know, I have been roasting beans since approximately 2007, and I have been through about three popcorn machines. They are easily trashed by the beans, grow dark on the inside, and with experience, I have learnt not to melt the plastic top. So: don't expect to be using your popcorn machine for actual popcorn after a few roasts. There are plenty of quality coffee roasting machines out there, but I get decent results with Cornelius for the small amount of coffee that I roast. Saying that, an I-roast 2 would be a wonderful gift someday (hint hint, Food Critic Andrew).
OK, so aside from a popcorn maker, I also need 2 large mixing bowls. One sits underneath the outlet of the popcorn maker, and catches any flying beans. They usually stay inside the popcorn maker, and a few lighter weight beans usually find their way out. It also catches the chaff, which is a waste product of the process. Some types of beans have more chaff than others.
I use the measuring cup provided with the popcorn maker to measure out a heaped lot of green bean. Then put it into the popcorn maker, and turn it on. Let the beans roast until they are your desired roast. This depends on the type of bean, I prefer a darker roast, because I drink milk based coffees and like the richness to come through.
Here is an excellent visual guide. Using this scale, I roast my beans to approximately 12-13.
After the mixing bowl is filled, I leave the beans to cool, and then package with the date. I tend to find that the beans I prefer take 7-14 days to mature to their full potential. Of course, others may vary. The chaff goes into the garden.