Housing
This frog needs a large, warm body of water and some plants (buy these from your local pet store). Make sure you use dechlorinated water (add dechlorinating drops and let the water sit out for at least 24 hours before putting it in contact with the frog)! You can add river stones (not aquarium gravel!) as a substrate in the water part of the tank. Use non-chemical (and non-white plant food balls) potting soil with moss covering it as a substrate on the land. Never use cedar or pine shavings (toxic), gravel (abrasive), bark or sand (abrasive and ingestible) as a substrate! You can also add non-toxic plants and other hiding spots to the cage. Never use any chemicals when cleaning the terrarium! Just use HOT water and a paper towel. The substrate should be changed every week if not sooner.
Temperatures
Green Frogs require temperatures between 75 to 85 Fahrenheit. Use an incandescent bulb or undertank heating pad for accomplishing the right heat. Make sure the frog or the water from the frog splashing can't come in contact with the bulb! Hot rocks/sticks/caves should not be used due to the fact that they can cause thermal burns in frogs and other animals.
Diet
Insects (crickets, occasional mealworms, waxworms, and grasshoppers), spiders, other tadpoles etc. Instead of catching insects from the wild to feed to your frog, buy them from pet stores to greatly reduce the risk of feeding your frog disease/pesticide-ridden insects. Remember to remove all dead or uneaten insects/food items everyday.
Health
If your frog is cut or burned by something in its cage, remove the object and call a vet before applying any kind of medication due to the fact that some can be lethal to your frog.
Fungal infections are very common in tadpoles and younger frogs. They look like inflamed areas of the skin surrounded by whitish threads. In its early stages, it can be treated by immersing the frog/tadpole in a 2% solution of malachite green or Mercurochrome for five minutes, repeated again after 24 hours. A veterinarian should be called if the infection does not clear up.
Red leg is a common disease in frogs caused by bad husbandry. It causes small ulcers, hemorrhages, and reddening of the skin around the belly and underside of the thighs. The infected frog should be kept warm (85 F) and immersed in a 2% solution of copper sulfate or potassium permanganate.
You should always at least consult a veterinarian if you think there is something wrong with your frog!