Help them learn to recognize it and, if they're interested, write it. Subscribe to a children's magazine. Getting something in the mail whets children's interest in reading. Point out words on cereal boxes, restaurant signs and other familiar items. Take them to the library.
Kids start developing their own taste in books before they can read.
Celebrate the magic moments when they can truly sound out words or read a simple book they've never seen before. Encourage them to write simple stories. Don't worry much about spelling errors at this stage. If you want to correct misspellings, do it after you've praised the content of their writing. Let the kids help you look things up.