One of the things that's wonderful about Facebook is that it helps you stay connected with some of your past and present friends and family.
The problem is when Facebook takes over your life and you spend too much time on it.
What I have found the solution to be is to get on it on "breaks" from my daily life. I find Facebook somewhat relaxing so I use it for my break. You can get on Facebook for short periods of time but keep it to that, short.
Also, I like to keep my posts "positive" and not too personal. The exception would be if there is something very challenging in your life and your friends could offer you support, but don't abuse it. I have found this tremendously helpful at those times and my friends are wonderful. Try to keep your posts from boring people. For instance, Nobody wants to know that you woke up tired. Post something interesting or nothing at all. Don't fight with your ex on Facebook. It's just not the place. Do that in private. If you have a beef with someone, send it in a message, not for the world to see.
I would love other helpful comments.