Two more Jewish cemeteries in the New York City are in the process of coming online with searchable databases so I thought I would post a list of links for all of the ones I know about.
First, a few search tips. Enter as little information as possible in the search fields. This will give you more search results to look through but will also catch spelling variations. For the first five cemeteries listed you have the ability to search by section and society. Once you locate an ancestor, you can then search for that section or society to see who else is buried there. You never know who you'll discover!
Mount Carmel Cemetery, Ridgewood (Queens), NY
Mount Hebron Cemetery, Flushing (Queens), NY
Mount Judah Cemetery, Ridgewood (Queens), NY
Mount Lebanon Cemetery, Glendale (Queens), NY
Mount Zion Cemetery, Maspeth (Queens), NY
Riverside Cemetery, Saddle Brook, NJ
And the two new ones...as of this posting date these are still a work in progress so if you don't see someone you're looking for, try again later. Right now there isn't the possibility of searching by section or society. I hope they add it later.
(Old) Montefiore Cemetery, Springfield (Queens), NY
New Montefiore Cemetery, West Babylon (Suffolk), NY
HAPPY HUNTING!! :-D