You have been given some wonderful advice here already for you to consider. I think that a lot also depends on your family situation, your children's personalities, and their life experiences.
I can only share what I chose. My children are roughly the same age as yours, 15 and 11. I know they have seen me drinking and have seen it's effects on me. I also believe that actions speak louder than words. Over the past two years, I have had some wonderful stretches of sobriety have made some huge changes in my lifestyle and behavior. I would like to speak with them one day about it all, but think it's best to do that when I am more confident and comfortable in my own sobriety.