I love the preschool years. Children at that age are so full of wonder and questions, and Mom and Dad are still the smartest people in the whole wide world. They love to mimic what is around them, and we can give them good examples or poor. In the area of reading, your best example is to read, read, read and read some more. Your child benefits not only from being read to but also from seeing you read. Reading families tend to grow reading children.
Reading to a child helps to develop his imagination, his understanding, his character as well as his desire to read. The pictures in a child's head that form when they listen to you read are far more imaginative than any TV show or video.
You will be amazed at what you cover naturally in any given day. Try an experiment. Write a journal of the activities you do with your preschool/kindergarten child in a day. Try classifying what you do into academic subject areas. This also helps in seeing what you don't cover. This is a helpful practice you can take with you into your child's school years as well.