Hi Megan,
For me I think this falls into two different categories:
1. Books I love using for my own ID, protocols, etc.
2. Books for the public
For myself, some of the USFS reference guides, as well as DNR pocket guides are my go-to's, especially since many are small enough to put into my field pack to take with on our field days. Others I have recommended to the typical office visitor/outreach attendee include "Bringing Nature Home" by Tallamy, "Attracting Native Pollinators" put out by the Xerces Society, and "Landscaping with Native Plants of Michigan" by Steiner.
I'd be happy to give some more recommendations if you want to directly chat, otherwise happy book hunting!
Elise