Matt Galyon at the Prima Coffee blog provides simple steps on choosing coffee:
1. Detailed Information on Where the Coffee Came From
Look for the name of a region, co-op, or farm. The more information as to where a coffee originates, the greater chance you will be getting a higher quality, more uniform coffee rather than a blend of different coffees from the same general region.
Coffee should generally be used within a month of the roast date with the peak flavor hitting 7-10 days post-roast.
Look for a plastic seal with a small hole in the center on the coffee bag. This is a one-way air valve that allows the CO2 emitted by the coffee to leave, but keeps out oxygen. Exposure to outside air speeds up the aging process.
While some people prefer the taste of a darker roast, lighter roasted coffees better represent the particular flavor profiles of the bean and its place of origin. The darker you roast the coffee, the more you taste the roast itself rather than the unique characteristics of each bean.
Look for lighter roasts only when all other criteria are met; sometimes roasters will use their roast style as their selling point while skimping on bean quality.
Information on the processing method used for the coffee, the date the coffee was harvested, what varietal of tree the bean comes from, elevation the coffee was grown at, and recommended brewing paramaters for the coffee are all signs that the roaster knows and has taken care of the coffees they are selling you.