mrsselby,
Ignore any writing. He's supposed to do scribbles. If he likes to color, you could print out capital letters for him to color, just for continued recognition purposes, but no writing beyond what he's doing naturally; with chalk and fat crayons. Tracing in the sand or finger paint, using magnet letters, etc. Try not to have him even tracing letters too much at this age unless it's just something he wants to do otherwise he'll end up hating writing in the future. Having him use his finger to trace over the letter, or a crayon or chalk; but even still, he's really young for that, too.
Gently teaching sounds and reading aloud are sufficient. Jim Weiss does have a wonderul phonics audio listen and read-along book called Abadaba Alphabet that my dd loved and he's at a great age for it now and for a while.
Rachel
