Talking to children about sex can make people feel a little bit uncomfortable. But the important thing is you begin to do it when they begin to ask questions. So if you happen to have a 4 year old and they ask "How did the baby get into your tummy mommy?" Which is what happened with me, that's the time you begin giving them answers - simple, concrete, age appropriate answers. Tell a child that you're the place to come to as the source of information. But if you shut them down early, "The stork put it in there. I don't know" then they will go out to the school yard and get misinformation later. Now, if you have waited until they are middle school and hitting adolescence and you're realizing you've got to get to this, then I'd say the first thing is to make sure you're clear within yourself about what your morals and values are so that you can impart them very calmly to your child as family values. Secondly, when you do get that lesson about sex, make sure it's not just a plumbing lesson. It's not a biology class. We want to talk about the emotional consequences of sex. We want to talk about how sex can be a bonding experience. The various meanings of sex. Try to not be judgmental and angry and sex-negative. You want to be sex-positive but you also want to show boundaries and you want to show the psychological piece as well and the commitment piece. And the other thing is, if you feel uncomfortable, do it when you're driving in the car and they're looking out the window. Do it when you're shopping and somewhere - just be distracted. You don't have to sit down and make it this big, heavy grave conversation. So keep the conversation light and loving so it doesn't overwhelm your kids and they can get the vital information they need.