Grinding your coffee beans just before brewing will help to protect the aroma of your coffee. Ground coffee interacts with the air around it and within hours can lose a great deal of its flavor and aroma. The longer you let the ground coffee sit around, the less aroma you will find in your coffee later. Remember to only grind what you need now. Don't get ahead of yourself and grind for the whole week! Once the beans are out of an airtight packaging, keep them in a dry, dark container with a tight closing lid.There are several different types of coffee grinders available.

The conical burr grinders preserve the most aromas and can grind very fine and very consistent. The design of the steel burrs allows a high gear reduction to slow down the grinding speed. The slower the speed the less heat is exposed to the ground coffee, preserving the maximum amount of aroma.
Conical grinders typically have a wide range of grind settings that are ideal for all kinds of coffee equipment Espresso, Drip, Percolators and French Press.

Another excellent type of coffee grinder is the burr grinders. Burr grinders grind at a faster speed than conical burr grinders and create a more warm flavor and aroma in the coffee. They are, however, the most economical way of getting a consistent grind in a wide range of applications. They are best suited for most home pump espresso machines.