Since you are in New York City, start there.
This link will take you to your state Corporation search:
http://app***t8.dos.state.ny.us/corp...y_search_entry
Those results will include, "business and not for profit corporations, limited partnerships, limited liability companies and limited liability partnerships, as well as other miscellaneous businesses."
It does not include everything, though. For DBA (fictitious business name filings), you'll need to check with your county, since that is where those are filed. Some counties have an online search, others don't.
The wizard at this site might be a great place to start, since it will give you a list of what you need:
http://www.nyc.gov/portal/site/busines***press
hee hee... those troublesome asterisks....

For both links above, replace the *** with a three letter word that starts with 's' and is another word for "gender".