You can find it here: http://www.state.nj.us/dca/codes/lt/pdf/t_i_r.pdf (Landlords should read it 3 times)
Not only can you get fined if you don't get a C/O, in some towns you can't even evict a tenant if you haven't registered your property with the town as a rental. The Landlord Tenant court may not accept it. This may vary by county. C/Os vary by town. Don't become a landlord unless you know what laws apply. How about Lead Based Paint addendum to the rental agreement if the house was built before 1978.
The other answers you received here are good (except for the one from Peter Rogers).
I can tell you - if you think you can fight with the town and win you are likely to be disappointed.
Joan Prout, MBA
RE/MAX Villa REALTORS
306 Grove Street
Jersey City, NJ 07302
800-671-0596 x1 (direct)
In some towns if you have a single family home that you are renting out and you are the owner.. yes you have to go and get a new Fire CO and such, not just single family.. anything you rent will have to be certified safe for the occupants.