Google AFL/CIO and your local town. Reach out to them with what your industry is, and anyone who is also interested in a union. They'll get back to you with either materials or a local rep that can guide you through the process. If after you've emailed you get a response feel free to reach out to me here and I can show you how to take the next steps, it's usually a communication network for your co workers. I can help out with some pointers if you like, after you get an email chain going.