Here are a few key ways you can make a difference. 
Read to your child every day.
Research into child literacy has shown that the more children are read to, the more effective they can become at reading and writing. It has been estimated that children need a minimum of 1000 books read to them. If that seems like a lot, by reading just three books a day you will have read 1000 stories in a year.
Enrich your children's vocabulary.
Using a wide variety of language will help your children develop a rich vocabulary. Children love big words like "fascinate" and "excellent".
Don't stop reading when your children start to read for themselves.
This is very important, as children will quickly lose interest if something is too hard. Reading should be enjoyable, not hard work. Keep reading, keep it interesting. Maybe it's time to start reading chapter books? A chapter a night means you can still share that special time.
How we read is just as important as actually reading a book.
Talk about the pictures. Speculate about what happens next. Explore feelings. You will learn about your child as you go and your child will absorb that much more.
Repetition
Dont get frustrated when a child asks you to read the same story over and over. There is some very good learning taking place. We all learn by repetition.