Surround children with examples of letters and words. Borrow different books from the library every week so children are exposed to new books all the time. Hang images of letters and words at eye level to children.
Introduce preschoolers to the sound each letter makes by using rhyming activities. Read rhyming books and sing rhyming songs. Point out words that rhyme by saying things like "There's a cat and there's a bat! Can you say 'cat' and 'bat'?" Point to pictures of letters on your walls and demonstrate the sound that each letter makes. Ask children to repeat after you.
Play audio books. Listening to an actor read a story makes it come alive and seem exciting to preschoolers. Borrow these audio books from the library or buy them online. Choose audio books that include a beeping noise whenever it's time to turn the page. Get a print copy of each book for children to follow along in. Explain that children should turn the page whenever they hear the beep so they can truly feel like they're "reading" the book themselves.
Teach the alphabet one letter at a time. Choose a "letter of the week" to focus on each week. Point out examples of the letter in the environment and ask children to look for examples. Pass out magazines and ask children to cut out all the examples of the letter that they find.
Make up stories with children. Ask children to think up their own stories and draw illustrations onto several pages. Ask children to describe each drawing and write the caption onto the page. Staple the drawings together to create books. Keep the books on a low bookshelf so preschoolers can "read" the words to their own stories back to themselves.