I would recommend doing some reading up at PFLAG (Parents, Families and Friends of Lesbians and Gays).
Here's some on its membership:
"Our members come from all walks of life. We are straight, we are gay and we are bisexual. We are transgender. We are moms and dads, siblings, grandparents, aunts and uncles, friends, children and allies. We come from large cities and small towns. We live in rural areas. We are people of color. We come from all economic backgrounds. We come from all faith traditions. We are disabled. We are youth and we are elderly. Our membership and our leadership are diverse, but what we have in common is our commitment to grow beyond false and harmful perceptions of LGBT people, to educate our communities, and to stand up for full equal rights and protections for LGBT people."
And here's the place to start if your son comes out to you or you want to think through this possibility:
http://community.pflag.org/Page.aspx?pid=539