While roasted beans are still fresh a week later, coffee begins to stale immediately after grinding. This is why it is important to grind just enough coffee for the number of cups you are preparing - and to grind it just before brewing. A good grinder is essential to good coffee - see what Coffeekid has to say.

The best type of grinder is a burr grinder, costing upwards of $50. The reason they are preferrable is that they grind the beans to a preset, consistent coarseness. Also, they don't burn the coffee as blade-type grinders can do. I personally use the Solis Maestro.

Whirling blade grinders are another option and can be found for as little as $12.00. They aren't as consistent in grind coarseness and take some practice to get the desired grind. Also, they can "burn" the coffee from the repeated striking of the grounds as the blade spins. There is one recommended blade grinder that seems to minimize this trait - the Capresso Cool Grind. It is available for about $20.

For more detail on grinding and the difference between blade and burr grinders, click here to visit coffeeresearch.org.