I started coming out at 16, first to my little godsister (who later turned out to be a lesbian), but it really didn't start rolling until I hit 17 and graduated high school. Then I worked up the nerve to come out to my dad. He didn't take it like I'd anticipated; I'd worked up this whole speech about it and he said "Yeah, we know. Want a beer?" Mom on the other hand wasn't nearly as accepting (at first). Now, she understands that had things turned out differently, then I wouldn't be the same person that I turned out to be....which is someone that she's come to respect, admire, trust, and become a very close friend to.
I decided at 22 that I wasn't going to play the selectively-out games anymore. I came fully out, and let the chips fall where they may. I've not regretted that move. Sure, I got snubbed by some folks and turned down for career moves, but I don't see those as losses, since neither friends nor careers are worth it to me if I have to live in fear of the repercussions for simply being myself.