For the time being, you can still use the 1987 SICs. Access to data gathered by trade associations varies. Some organizations offer extensive databases of free information, others limit data access to their paid membership. The best place to access information produced by commerical sources is your public library. Most larger public libraries are equipped with the databases you need to do your research.
Many articles are available full text.
You can also find some of this information on the Internet. This information is essential to your market plan. Census data is free and readily available on the Internet. Several commercially produced demographic materials are available at the Morris County Library. Commercial surveys, academic studies and opinion polls are often cited in general consumer and trade publications.