Has anyone ever gone through a mediation with the Commission on Human Rights or EEOC? What does it entail?

I filed a discrimination case against my past employer. I believe I was disciminated against or forced out so to speak because I had begun having trouble with my heart. I had a cardiac procedure done in January of 2011. From there, it was a nightmare. No reasonable accomodations were made and I was hled a lot at work. I am hoping someone has gone through this and can tell me what to expect. I cannot afford an attorney and this is a large organization.