There are some state census listings at the Ancestry site (http://www.ancestry.com), which is a fee site, though they often have free trial periods. New Jersey is not one of them. There are several New Jersey census films available from the LDS library. They were done on the 5's -- meaning, 1865, 1875, etc. I believe the last was 1915, but am not sure about the earliest. Having used the New Jersey films, I can tell you that the primary problems are a lack of index (unless there is one I never found) and the fact that you must already have a sense of where the person lived, because you must roll through countless images to arrive at the one you seek. The 1895 was good for me, but required patience.
: Are any of the State Census (asopposed to the Federal Census )available on-line? Iam particularly interested in New Jersey and New York.