Many members of my mother's generation did not even attend kindergarten. Many members of my generation did not even attend preschool. With my son's generation preschool has become a necessary part of the preparation for formal education. To get more detail about preschool education you can go http://www.lemanmanhattan.org/academics/early-childhood-program.
In fact, for most children, formal education actually begins with preschool. That does not mean that preschool education begins the first day of preschool. In fact, if you want your child to succeed in preschool and beyond then you must prepare your child for preschool. What are some of the things you will need to teach your preschooler?
You need to help your child become as independent as possible. This implies hygiene and toilet training in addition to the ability. Educate your child mentally and emotionally for the concept of freedom from other caregivers and you.
There are some concepts that kids must learn. These lessons will be solidified before preschool that's even better but if they are grasped by a child during preschool. Including knowledge of shapes and colors.
Do not spend a good deal of time drilling this knowledge but instead introduce it to life to your kid. Name the colors of the clothing your child will wear. Point out shapes throughout the day or even cut food.
Then as those are mastered and begin working with your toddler to present the letters of the alphabet start introducing the beginning letter sounds. As you go about your everyday routine make these classes casual and fun. Begin working on counting as you cook, clean and dress.