Pull out the old magazines, or newspapers lying around the house. Cut out pictures you know your child will recognize, such as dog, bird, fish, hand, ring, and other simple items.
Teach one letter and sound a day.
Show him pictures of things that start with a particular letter. For instance, d and dog. Show him the picture of the dog, explain dog starts with /d/ phonic sound, and present the card with the "d" letter on it.
After naming several things with a /d/ sound, ask him to name other things that start with the same sound as dog.
You want your child to be able to recognize and read the same sounds over and over, until they're sure.
Use consonants and wait on vowels. Vowels are special because they each have 2 sounds, a long and short sound.
You want simple, not complex at this point. Many children learn to read beginning phonic sounds with consonants.
Create an alphabet folder with your child.
For each letter, purchase a ten cent folder and write the letter (both upper and lowercase) on the front. Once he understands beginning phonic sounds, look for pictures together that have the same beginning sound as the one you are working on.
Glue the pictures to the front of the folder and on the inside pockets. If it gets full, add construction paper and slip in the pockets.
Use trips to town and other opportunities to nurture his skills. On a trip to town, point to objects and ask your child the beginning phonics sound.
Make it a game. Play along and allow him to ask you the beginning sound of objects as well. Games make learning to read seem easier.
Practice, practice, practice.
Once in kindergarten, tests on Initial Sound Fluency are administered in the beginning, middle and end of the year DIBELS assessments (Dynamic Indictators of Basic Early Literacy Skills.)
Use other helpful tools. Computer games, alphabet books, read alongs and other games encourage Initial Sound Fluency.
Starfall.com is a wonderful resource. Those old "pull the chord and hear the sound" toys are still beneficial, too. Teaching a child how to read doesn't have to be expensive and complex.