Hi Deb,
The ideal way to get around
New York City is walking, specially during the spring months when the
weather is great. As you taking your kids with you, you may want to take the
subway more often, in which case you could buy a weekly pass which is around $18. As you may be aware, NYC is a very busy city and a congested one, which is why I recommend walking as much as you can.
If you would like more information on what to do in NYC, please check out this link:
http://www.destination360.com/north-...k/things-to-do
By the way, It is around 22 miles (35 km) between JFK and Newark International Hotel.
Hope this helps
VacationBuddy