Here is a starting list. Friends shared several suggestions . . . Nancy Brown had many to share on the topic as well. I also found many on my own. Reviews to come!
Last Child in the Woods by Richard Louv
The Nature Connection by Clare Walker Leslie
Keepers of the Night by Michael J. Caduto and Joseph Bruchac
Keepers of Life by Michael J. Caduto and Joseph Bruchac
Mixed-Media Nature Journals by L.K. Ludwig
Handbook of Nature Study by Anna Botsford Comstock
Pond and Book by Michael J. Caduto
The Field Guide to Wildlife Habitats of the Eastern United States by Janine M. Benyus
Ecology by Enest Callenbach
Life in the Soil by James B. Nardi
Nature for the Very Young by Marcia Bowden
The Nature Principle by Richard Louv
Insects by Donald J. Borror and Richard E. White
101 Trees of Indiana by Marion T. Jackson
Mammals of the Great Lakes Region by Allen Kurta
The Sibley Field Guide to Birds of Eastern North America by David Allen Sibley