You don't need an alphabet book to teach your child about letters.  Any picture book presents opportunities to talk about letters and the sounds they represent.  Ask your child if he sees any letters that are in his name.  Being naturally egocentric, preschoolers are the most interested in their own names and the names of those close to them. 

Anton Can Do Magic by Ole Konnecke is great read-aloud for preschoolers.  It has simple pictures with lots of white space which makes it easy for the youngest children to interpret.  The text is brief and much of the story is revealed through the pictures.  See if your child can explain why Luke thinks he's done a magic trick...