This book contains some useful advice on what to consider when evaluating children's books, and a wealth of references to worthwhile children's books, but it was fairly dull.
Too much time, I felt, was spent on tangential issues, such as details of publication, what are endpapers, what is the difference between a printing and an edition, and so forth. While of course it is useful to know the right terms to use when discussing a book, and some insight into the publishing process can be helpful, ultimately this feels like it takes up a disproportionate amount of space in what is a fairly short book.
My other major criticism is that the wealth of references to children's books, which I mentioned above, is both a strength and a weakness. For example, Horning spends some time discussing how the illustrations in a picture book should support and enhance the text, using Goodnight Moon as an example. For readers unfamiliar with that book, this discussion will be far less helpful. Not too big of an issue with such a very popular book, but many other, less well-known books are mentioned as good examples of a type, without a great deal of explanation why--it would be necessary to acquire and investigate each of these books to understand the points Horning makes.
From Cover to Cover is useful, but doesn't stand alone as a complete guide to evaluation and review of children's books.