It takes a lot of courage for someone to come out to you--listen to all they have to say without interrupting, judging, tuning out or buying into stereotypes about LGBT people.
Tell them how pleased you are that they trusted you enough to share something so personal and congratulate them on the bravery it took to be so honest.
Let them know that you feel the same way about them as you always have and that nothing has changed (except that you can be even closer than before).
Ask questions and show that you are interested in learning about their feelings and experiences. Be respectful and stay away from personal issues (sex, HIV, etc.) unless they let you know it’s okay.
If you are feeling uncomfortable or upset, be honest. Let them know you may need some time to process everything, but acknowledge that it is your problem to work out and not their responsibility.
Remember that you cannot and should not try to change them--you have an opportunity here to support, not to reform them.
Ask what you can do to support them or what they need from you right now.
Follow up. The coming out conversation should be the first of many. Continue to check in and ask questions over time.
Be open to socializing with their new friends and in a variety of settings, both LGBT and straight. Let them know that they don’t have to compartmentalize their lives.
Be an advocate. Read up on LGBT issues, wear an LGBT-friendly button or sticker, join a GSA or other LGBT group, and confront homophobia in whatever ways you can.