According to New Jersey State, if you are conducting "a business in New Jersey, you must register for tax purposes by completing Form NJ-REG, which is contained in the Business Registration Packet."
This form may be completed online or you may download the forms and instructions. Here is the link, if you wish to register for taxes in the State of New Jersey. Registering for Taxes
Follow the instructions as required and the process is fairly easy and user-friendly!