Lib Web Cat
The Advanced Search page of lib-web-cats is designed to help identify libraries according to the library automation system they use, collection size, and affiliations.I found this in my rounds and thought it might be of interest to you. Basically you can search for library collections all over the country, if that happens to be your wont, by size and affiliations. It would be heavenly if you could limit your searches to children's collections and where the best ones are, but as of yet the site doesn't allow for that search term. If your library system has not submitted its information, consider doing so. The lib-web-cat is run by Marshall Breeding, the "Director for Innovative Technologies and Research for the Jean and Alexander Heard Library at Vanderbilt University", so it's on the up-and-up.