I guess it depends on what you want your story to be about and what kind of information you need for it to be believable. In a fantasy setting, I don't think any research is really needed, unless you want to include struggles of discrimination?
In my own stories (unwritten), it's a non-issue. I just treat it as "normal," but then normal is different for different people; but I like fantasy to escape the real world.
I think as a general rule, remember that people are people and just, treat them like people.
