As a reader and a writer, I love social issues. One of my earliest favorite books was Are You There God? It's Me, Margaret, which dealt with a sixth grader's search for religion, as well as acceptance from her group of friends. In fact, I loved all of Judy Blume's books as she told stories about young teens dealing with divorce, masturbation/early sexuality, scoliosis, and young love.
I also enjoyed the stories of 'I was A Teenage Alcoholic/Drug Addict/Runaway'. I think I checked the teen alcohol addiction one out of the library so many times, my name was the only one on the entire card.
I learned to stay away from these pitfalls of the teenage years. And they weren't told in a preachy manner. No; quite the opposite. Sometimes it was rather humorous.
And that's what my alter-ego has tried to do in her books; weave the social issues into the story lines in order to show how even good kids can make disastrous choices. Throughout her series, young women learn the choices they make can affect their overall outcome in life. Sometimes it's a good change; other times not so good. As one reader put it, as she identified with a particular character, "It's nice to see what my life would have been, had I stayed on track."
As for me, I don't consciously add in a social issue; it just happens to sneak in. For instance, I had no idea sexual harassment would rear its ugly head in Teacher's Pet. I had to stop writing for two days and research. In All She Ever Wanted, my expanded chapters suddenly dealt with health department citations. Again, I had to stop and research.
In Wild At Heart, gambling addiction showed up. Off The Clock shows a young woman who's the sole caregiver of her Alzheimer's-stricken mother, and the horrific issue of elder abuse (not the woman, but her brother).
So my advice to anyone wanting to write about issues, be it political, gay rights, whatever...weave it into the story in such a manner it does not come across preachy. The reader should not even realize they are being educated until after they're finished reading.