If you've already mastered the basics, you may want to look at other books such as "The Crockery Cook" by Mable Hoffman (Fisher Books) or "Ready and Waiting," by Rick Rodgers, which offer more sophisticated fare. You can also adapt some of your favorite recipes to a slow cooker. But if you have only 15 minutes in the morning for prep time, you will want to keep it simple.

Slow cookers have become more sophisticated, with more heat levels, programmable settings and lift-out pots. But the concept is still the same — "It's basically a little tiny oven," said Williams.

Advantages of slow-cooking:

— Moist, flavorful food. It doesn't dry out because the steam rises to the dome-shaped lid, where it condenses and drips back into the food.

— You can save money by buying inexpensive, tougher cuts of meat such as pot roasts or ribs, and let the moist, gentle heat tenderize it.

— Because of its size, it's easy on electricity and you don't heat up the kitchen.

— You don't need to watch the pot. In fact, it's better if you don't peek, because lifting the lid lets the heat out and adds about 30 minutes to the cooking time, say Ashcraft and Eyring.

— It's portable. Since the crockery retains heat, it can remain unplugged for an hour. But if your travel time, plus waiting time, exceeds that, you will need to plug it in to keep the food hot enough to avoid food poisoning.

— Cooking times are flexible; your dinner isn't ruined if you're a half hour late getting home.

— The food retains nutrients and flavor. The liquid in the pot is usually made into a sauce or gravy, so even the water-soluble vitamins that leach into the liquid are consumed, said Williams.

— Easy preparation and cleanup. Because you're usually cooking in one pot, you don't have other pans to wash. The pot can go from the counter to the table, and if it's a lift-out pot, it's even easier to clean.

But slow cookers have their drawbacks. You need to plan — you can't throw together something at 5 p.m. and expect to serve it at 6. Also, rice, noodles and pasta, and fragile veggies like green peppers, tend to turn mushy with a long cooking time. Generally, it's best to add them 30-60 minutes before serving. Milk products like sour cream can curdle, so they should be added at the end of cooking time.

Williams advises against cooking ground meat in slow cookers because it should be cooked quickly to avoid the growth of potentially harmful bacteria. So when making chili, lasagna, etc., brown the ground meat first in a frying pan, then add it to the pot.