Hi Steve,
These resturants are really amazing.
Pure Food and Wine - All organic, live, vegan food. If it's warm enough, try to get a table in the garden!
http://www.purefoodandwine.com/
Quintessence- Also organic, live, vegan food. Small and busy, so maybe avoid peak times. Worth the wait though! They only have the one location in the east village now. (10th street)
http://www.raw-q.com/
Candle 79 - AMAZING vegan, organic food, but not raw.
154 East 79th Street near Lexington Avenue, New York, New York 10021 Phone (212) 537-7179
Monday - Saturday Lunch 12:00pm - 3:30pm Dinner 5:30pm - 10:30pm | Sunday Brunch 12:00pm - 4:00pm Dinner 5:00pm - 10:00pm
This book is also really helpful. Although a couple of places in there have shut down, so call before hand.
http://www.amazon.com/Vegan-Guide-Yo.../dp/0978813200
Oh and definitely go to Central Park. Is is so beautiful there!!