The best tool for researching anything legal is the Internet. Not only can you find the entire text of the law, you can see how that law is usually enforced. In Appendix E, you will find a list of websites that will help you in your research.
If you prefer using books for your research, your local library or a law school library may be able to help you. If you are going to file a complaint with a particular agency, that agency may have written information for you and sometimes may have a research center open to the public.
Remember that the law that is actually enforced is not exactly what is written in the statutes. The law is constantly evolving through judges interpreting the statutes. The law, especially employment law, is not black and white. In employment law, whether something is illegal or not depends on the circumstances surrounding each individual case.