I recently had to answer a question on selection criteria for children’s books (as part of my course work). I framed it as a checklist, and post it here in case it proves useful for anyone buying or selecting books or poems for young readers:

Does the book or poem achieve one or more of the following through its use of language:
• Enchantment and wonder
• Authentic emotional engagement (free from sentimentality)
• Intellectual and educational challenges
• Nourishment for learning development
• Imaginative journeys?

Does the poet or author’s word and phrase choice offer attributes such as:
• Novelty and variety in vocabulary
• Rhythm or pace
• Respect for young readers (that is, not patronising)
• Delight in wordplay and sentence construction
• Compelling narrative
• Accessible or interesting style
• Engagement with well-formed characters
• Adequate grammar, form, syntax, scansion and usage
• Authentic humour and playfulness?

Does the treatment of the subject matter encourage or engender:
• Reflection or questioning
• Knowledge or understanding
• The pleasure of reading (and writing)
• Appreciation of language and listening
• Enjoyment?

Note: this is only about language/text, not illustrations or design. I might get around to that another time.
Other suggestions are, of course, welcome.