Hi! I'm long past coming out and well into transitioning, but I wanted to share with some of you who may be just starting down the path a way to come out.
I had a Facebook page in my former name, and rather than keep it (and a sort of remnant of the past, such as old posts referencing my old name, etc.), I opted to make a new page with my new name. What I did was post a comic on the old page basically explaining what was going on, left it up for about 4-5 months, then deactivated the old page. The idea was that if someone cared enough to look at my page, then they cared enough to know what was going on in my life, so they could know about my transition. Everyone else....well, sorry.
As a fan of ->-bleeped-<- and their Rage Comic section, I chose to make a comic using that to sort of reflect my personality and ended up with this:
http://imgur.com/qvdMh3SAnyway, keep it lighthearted and don't worry about reaching every person out there. This method is good for people you would like to tell, but want to keep the details limited. For the more important people, tell 'em in person or in a more personal manner.