How did I come out?
Well, as far as my family went, I sat down with my parents and told then straight up. My exact words were "I think I'm actually a woman".
My Dad took about 30 mins to get his head around it, and from then on he never ever once accidentally called me by my old name or old gender pronouns. My Dad is great.
My Mom on the other hand took it very badly. In fact she was unable to meet me or speak to me at all for 6 months. I just had to give her time, and eventually she accepted me. She later said it took her 6 months to mourn the loss of her eldest son (me), and 'replace' him with me in her head. She's fine now and we're closer than ever.
At work, it went very smoothly. At the time I worked for a very large company with over 20,000 employees. I told my HR department about my situation, and gave them a year's notice of my intending transition. They worked with me to educate and inform my co-workers about the whole transgender thing. There was a company newspaper, and when I transitioned, they did an article about me with a photo of the 'new me'. So then 20,000 people suddenly knew, everyone knew. And you know what? It all went very well. As long as you handle yourself well, and are confident, you should be fine. There is a lot more support and understanding of trans people these days. 16 years ago when I transitioned, it was still fairly new to most people.
If you really are sure it is something you need to do, then the earlier you can do it, the better. I wish I had had the courage and wherewithal to have come out when I was 20, rather than waiting for another 8 years.