Read books with a picture of a letter and a picture of an object that starts with that letter.
Play "shape" games with your baby such as simple shape puzzles or stacking games. While playing with these toys, talk about their shapes.
Provide large (6" or bigger) foam letters for your baby to touch and feel. Supervise your baby while she is playing with these letters.
Read books with your baby and point to and say the names of letters. Talk about your baby's favorite toy and how it starts with that letter, etc.