Several of my good friends, including my best friend, are gay/lesbian/queer. All of them have told me that coming out was one of the most emotional and difficult things they've ever had to do. Their parents' reactions ranged from shock and vulgar ignorance ("You mean you like to do it in each others' [censored]?") to rejection to loving acceptance.
How should a parent react when their child comes out to them? Obviously some reactions are more positive than others, and ideally all parents would love and accept their child as they are, for the person that they are. However, not all parents can do that -- this is the case I'd like to address as much as possible. What should a parent do after the initial shock has worn off? How can a parent prepare (as much as anyone can) for what could be a very surprising conversation?
I'm going to request an emphasis on professional opinions and cited studies in addition to personal experience.