Parents are really a child's best teacher -- day care workers and pre-school teachers spend only a few hours a day, perhaps five days a week with your child, in a somewhat artificial setting.
You, on the other hand, have been with your child under the widest variety of circumstances -- from before the moment of birth to the present time -- often twenty-four hours a day! You've observed your child go through the most significant learning events of his life, from the first step, to the first spoken word, to the first scribble, and so forth. Hence, you have the qualifications to serve as the resident learning expert when it comes to the education of your child!
Acknowledge the expertise you possess and use your knowledge of your child's learning ability to help him progress further in his development. When he encounters a learning difficulty, think back to previous victories and try to provide the support and encouragement he needs to move through present obstacles.
When he achieves an important learning goal, celebrate this with your child in some significant way. Above all, trust your deepest intuitions about how best to teach your child. Very often you'll find they're the correct ones.