GrowNYC has guidelines and more information here.
But in a nutshell, here's what you can bring:
Fruit and vegetable scraps, non-greasy food scraps like rice, pasta, bread, cereal etc., coffee grounds & filters, tea bags, egg and nut shells, pits, cut or dried flowers, houseplants and potting soil.
Here's what NOT to bring:
Meat, chicken, fish, greasy food scraps, fat, oil, dairy, animal waste, litter or bedding, coal or charcoal, coconuts, diseased and/or insect-infested houseplants or biodegradable plastics.
To see more details about our nearby locations or learn about other drop-off points in the city, please see this link.
In addition to taking a big chunk out of garbage collection, composting produces nutrient-rich soil that the City can used to nourish our street trees and our parks. One day, composting will be like recycling; it will become a reflex for anyone in Manhattan. And we will feel as if we've been doing this all our lives.
Addendum on 7/18: The New York Times has a good piece on how buildings are promoting the collection of organic waste here.
By Caitlin Hawke