Re: fireplace: you absolutely must make sure your flue is open and clear before you try to start a fire, unless you enjoy a smoke-filled house and CO poisoning. Clear anything flammable away from the fireplace. Get a screen if you don't already have one. If you're really worried about the fire spreading, get a bucket of sand or a fire extinguisher and keep it nearby. Actually, you should probably have a fire extinguisher for other reasons, too :P.

The best way to let it go out is simply to stop feeding it and let it fade on its own. Again, a bucket of sand may be useful if you must put it out ASAP, but then of course you'll have sand in your fireplace.