The easiest and quickest is from Barbara Kafka in her Microwave Gourmet book - do it in the microwave. Here is the recipe (I just did it yesterday and it works great):

4 bulbs of garlic, cut off a little of the top to reveal the tops of the cloves
1/3 cup chicken broth (or vegetable broth or water)
3 Tablespoons olive oil

Put the bulbs of garlic in a 4 cup measuring cup. Add the broth and the olive oil. Cover tightly with plastic wrap. Place in the microwave and cook between 6-8 minutes (depending on the size of the bulbs). Remove from the microwave and let it sit for 10 minutes. Then make a slit in the top of the plastic wrap with a knife (to release the steam) and then pull off the plastic wrap. Use your garlic or cook with it. It is now ready to use.

So easy and the cloves come out smooth and creamy as if you had roasted it for 45 minutes. Yummy.

RisaG