I often thought about this question, but never did it in the real world. Here, in the virtual world, I feel safe to stand to my real feelings.
If you want to come out to your friends, you’re brave. Normally the most of them will accept you, but you will also meet with the one or other refusal. Some will confirm “we always knew”, some will not like it. I would act with discretion, starting with a close friend you really trust and start with showing some indications. Might be, his reactions encourage you.
You must expect, if you let the cat out of the bag, news can spread like wildfire. Therefore it’s important that you think about your first steps.