This is a tricky one, because not everyone will understand, especially not with the same methods. With my friends, it was matter of telling them what was going on, and giving them the opportunity to ask questions if they had any. Really, you need to understand yourself before you can get other people to understand. That in itself is extremely difficult. It took me years before I understood, and my understanding now comes from a lot of research and a lot of self discovery.
What really clicked with me is thinking of it as a medical condition, or birth defect, because there is proof that points in that direction. It's also much easier for parents to understand this. My mom, for instance, needed a lot of information from research studies and from personal accounts to finally understand what it is I'm going through. Now, not everyone is comfortable with that conclusion. A lot of people attach a negative stigma to the "medical condition" label, but realistically... why would you treat something medically that isn't medical? This website seems to explain it well. (Though I haven't looked through it all, so I'm a bit apprehensive about giving it as a source. The page I'm linking is good for explaining the necessity of the diagnosis for receiving care, the rest of the site is yours to look through if interested)
DiagnosisThere are documentaries, of course, that can be helpful. (or not, depending on what you choose. Some send mixed signals so be sure that what you're trying to tell someone through a documentary or otherwise is what you want people to know, down to a T. Any misinformation can be harmful.)
One that I used in my coming out process is "Boy I Am", which deals a lot with transmen and lesbians.
Boy I AmThat's the link to the main site, the video is a little hard to find but I may have it still, and I would be able to help anyone who is interested track it town.
Letters, too, are a good medium. Try and explain all your feelings, explain that they are valid and that there are many people who feel the same way as you do. Though, first, I would urge you to figure yourself out first. That may need help from some people, so go to who you have to, but if you come out and then decide later that you have made the wrong decision it can kick you in the a** in the future. There will always be doubts, but the less of them that you have, the easier it is for you to make other people understand and accept you. As with anything else in life, confidence in yourself and your decision is key. If people see that you are happier, they will catch on. If not, they are not people who need to be in your life. Anyone who puts your happiness below their own comfort will be poison to your transition.
I just want to stress that a crucial part of this is allowing people to ask questions, and having the answers available. This will help with a lot of misconceptions. Even now, I still have people who mean well who don't understand that me being a gay man has nothing to do with my medical history, and that just because I was born female doesn't mean that I would be considered straight for being attracted to men. It's also crucial to be patient, and realize that many people have no idea about anything trans related, other than probably seeing trans people on TV before. Most people mean well and the questions they have are not attacks, and can get personal, but you do have a right to say you're uncomfortable with a question if it goes too far. Keep an open mind, because everyone else has to, too.
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