The first concept of the division of people into men and women, children learn at an early age, when they see people around them. If a child grows up in an intact family, where there is a mom and dad, then he just laid the information and become the norm. A more clear distinction kid can see on TV or accidentally became an unwitting witness to intimate scenes between the parents. In this case, you should not keep silent, but you need to talk to him, tell that this is a manifestation of love between adults.
If a child went to kindergarten, it is possible that after a while other children can tell him some intimate details. Of course, this information will be very different from the reality, and the children's perception of a very different, but discuss it with your baby is definitely necessary. In these conversations, a small child is not yet need to know the details of the physiological relationship should be more concerned with spiritual qualities. The process of the emergence of the baby into the world can be explained by the strong love between father and mother and a great desire to have children. Stories about storks and cabbage in modern children no longer held only if very small. Initially, this information is enough, just be nice to present it.
When the baby is a little older, intimate topic again become urgent for him. It will already be interested in the question of how he found himself in the stomach as came out, etc. It is important at this time not to run away from the conversation, or the thread of trust can be lost forever. If this period has come in 6-7 years, it is possible to give him a special literature, adapted to his age. There's a very simplified form describes the physiological process of showing pictures as the baby grows in the stomach. Also, you should definitely focus on what parents should love one another, be married and only then it will happen.
With the advent of the Internet, many children learn very early age for unnecessary information. Therefore, the house is worth to put the protection of such sites, restrict access to the network. Of course, this can not be completely avoided, but it is possible to minimize. Especially if the child already knows it from you, then it is not so interesting.
When it's adolescence, by the need to take the initiative for a frank conversation if a child does not make the first move. By this time he probably knows already, you just have to help him sort out these data, to talk about the consequences. It is important in this conversation to find the right wave, help your child to open up and not be ashamed of this theme. After all, if he does not trust you, it can do a lot of stupid things. It is important to convey to him that you can not rush things and try to enter into an intimate relationship with the first comer. It is very important the presence of feelings for each other, that there was bitter disappointment. You should definitely discuss in detail and safety in the process. If the child is worried about some details, do not be afraid, say what you know, and if there are difficulties, then read special books.
If your child has a sense of the priority rather than a physical need, then it is much less likely to get burned. Learn to respect yourself and others, as well as to seek and develop through life, build a good relationship of trust with each other, then go through adolescence offspring will be much easier. And do not blame the child for error if he had come to tell you about it, or else the next time he will not say anything more. It is much easier to control the situation, when you are aware of all the events.