These sites all have their own individualities. Some accept for review books published by small presses; others accept only books published by large, "traditional" publishers. Some don't publish reviews at all, but feature author interviews and/or excerpts from books/book details. I've indicated the latter type by "Announcements" (Ann.). Explore these sites and find what works best for you. Parents and others who buy books for children should find ideas for reading lists at these sites. I've tried to put something together that works both for children's writers and for those who buy children's books.
Abbreviations: MGR = features middle-grade book reviews; E-Bks. = accepts e-books for review; GPs = accepts guest posts; Int. = features author interviews; Give. = offers giveaways; Ads. = offers paid advertising; Lists = features book lists; Ann. = makes announcements; (F) = fantasy only; (R) = accepts guest book reviews; (I) = indies only
http://www.bookpleasures.com - MGR, Int.
http://geolibrarian.blogspot.com/ - MGR, Give., GPs
http://motherdaughterbookreviews.com/ - MGR, Guest reviews, Give.
http://book4children.blogspot.com - MGR, e-BKS, Self-pub. Bks., Give., GPs, Int.
http://www.beachboundbooks.com/ - MGR, Int.
http://project-middle-grade-mayhem.blogspot.com/ - MGR (recent or forthcoming)
http://mymcbooks.wordpress.com - MGR, Int., Give.
http://lisaisabookworm.blogspot.com - GPs, Ann.
http://dutchhillnews.blogspot.com - MGR, E-bks.
http://mundiekids.blogspot.com - MGR, Give.
http://advicefromacaterpillar.wordpress.com/ - MGR, Int.
http://peteredmundlucy7.blogspot.com - MGR, Int., E-bks., Give.http://justonemorebook.com - Podcast, MGR