Brian Cleary just came out with a great new series, Sounds like Reading... The books approach different phonics concepts, like short and long vowel sounds, with simple text, short instructions and Jason Miskimins bright, funny illustrations. The books are on display right now but they will find a new home in the Easy Reader section of the Parkland Community Library's Picture Book collection.
Cleary also writes the Words Are Categorical series and explains parts of speech (nouns, verbs, adverbs, etc.) in silly rhyme. Brian Gable's illustrations make grammar a whole lot more fun than I remember it! This series is split between the Picture Book collection and the Juvenile Non-Fiction section (J 428 CLE, for the most part).