My daughter enjoyed the 红蜻蜓学前阅读计划 Odonata Chinese Leveled Reading Series, a story-based curriculum that teaches 1200 Simplified Chinese characters. The series comes with workbooks, flashcards, and CDs which can be purchased separately.
四五快读 is an excellent, low-cost curriculum that teaches 825 simplified Chinese characters through stories and various reading exercises. Our reading skills improved considerably thanks to this series!
The Greenfield 我自己会读 I Can Read series has 96 short, humorous children's stories that are illustrated beautifully and build reading confidence. The CDs give exposure to native Mandarin or Cantonese. In addition, workbooks and flashcards are included.
Sagebooks is an excellent curriculum that uses spaced repetition and short stories to teach kids how to read 500 Chinese characters and basic sentences. Simplified and traditional Chinese versions are available.