A ten gallon tank will hold 3 newts. Give a small land body and a few aquatic plants. Fill it to the top and place a lid on firmly, they are strong for their size. Room temperature is perfect. If you wish to hibernate keep them at about 40 degrees Fahrenheit for a few weeks and them warm them up slowly when you re ready to bring them back out. Feed them freeze dried tubifex worms, but not all newts will take this item. If they reject this, you can feed them earthworms, crickets, mealworms, etc.
What the person above said is all fine and dandy, but you need to make sure you thoroughly research your animal because he/she lacked proper detail.