Tell them what you're doing and ask questions. Encourage your child to talk to you. Have them describe events and talk about their activities and experiences. They will learn how language works. Make play activities and everyday activities occasions for reading development.
Small children learn best by playing, rather than by being instructed.
Let your children choose their own books to read. Allow your child to get a library card. Build your personal library. They will be enthusiastic about reading. Listen to your children read.