When you check on hotel/motels online, see or call whether they have shuttles to NYC. It is dangerous to drive to town.
When you are in NYC, you can buy tour bus tickets that allow you to get off the bus on many famous sites. The ticket is about $70-100/per person for 24 hours if I remember correctly. This is good if you have young kids and parents. If not, you can buy a whole day subway ticket.