Facebook is a great place to share photos and short sentences. I particularly like to post photos of my dog, and they usually say that she is sniffing around. I try not to go into too much detail because Facebook is a place for photos and captions. Anything beyond that, even a paragraph or two, is too long.
So if you want say more than "here's my dog, she's doing great today" and getting a bunch of likes and comments like "what a good dog! Reminds me of one I used to have", it's time to move to a blog. A blog will let you write several paragraphs, and people will actually read it, because, well, it's a blog, not a caption of a photo.
If, for example, you have a Facebook page about True Crime in Phoenix, chances are that you are the real expert there. Other than a few "likes", most people won't really contribute much, unless, of course, they are linking to a blog. And a blog is what you should be doing. This is how to start:
• Make a personal connection. No, we know you're not a professional writer, but maybe you delivered to some of the local establishments that gained fame. So write something like, "When I delivered beer to The Golden West, I had no idea that..." and then talk about what happened there. Yeah, you may be regurgitating stuff that people can find by reading through books, but you are putting a personal viewpoint on these things, which is what makes a blog interesting.
• Avoid the temptation to talk about yourself. Shut. Up. You're interested in True Crime in Phoenix - we get that. We don't need to know, and we don't care about, your personal life. This is a mistake a lot of speakers make - they suddenly find themselves in front of an audience and they immediately go into "boring old guy mode". Talk about your subject. Go into it right away.
• Don't connect blog posts together. Don't tell people about another blog post you wrote, or that they should go find it. They won't. Make each blog post self-contained. If you've written about Charlie Keating before, that's fine - write some more. And write as if your readers haven't read your other posts, and have no intention of doing so.
Writing a blog gives you a wider audience than posting on Facebook would ever do. So go write something interesting!