http://www.closureathome.com/About_Us.html
Highly recommended.
We hoped ours would die in her sleep so that we wouldn't have to make that decision but after researching we discovered that most don't go peacefully in their sleep. Unfortunately many more die from organ failure, dehydration, or even starvation because they feel too sick to eat.
Euthanasia was the best choice and having it done at home was the most compassionate thing we could do.